U.S. patent number 9,688,605 [Application Number 15/103,119] was granted by the patent office on 2017-06-27 for organic salts of glyceride-cyclic carboxylic acid anhydride adducts as corrosion inhibitors.
This patent grant is currently assigned to THE LUBRIZOL CORPORATION. The grantee listed for this patent is The Lubrizol Corporation. Invention is credited to Mark J. McGuiness.
United States Patent |
9,688,605 |
McGuiness |
June 27, 2017 |
Organic salts of glyceride-cyclic carboxylic acid anhydride adducts
as corrosion inhibitors
Abstract
A corrosion-inhibiting composition includes a diluent and a
mixture of organic salts of half ester-half acids of a dioic acid
with of a glyceride group with a fatty acyl residue. Included are
organic salts of glyceride-cyclic carboxylic acid anhydride
adducts.
Inventors: |
McGuiness; Mark J. (Chagrin
Falls, OH) |
Applicant: |
Name |
City |
State |
Country |
Type |
The Lubrizol Corporation |
Wickliffe |
OH |
US |
|
|
Assignee: |
THE LUBRIZOL CORPORATION
(Wickliffe, OH)
|
Family
ID: |
52282875 |
Appl.
No.: |
15/103,119 |
Filed: |
December 5, 2014 |
PCT
Filed: |
December 05, 2014 |
PCT No.: |
PCT/US2014/068707 |
371(c)(1),(2),(4) Date: |
June 09, 2016 |
PCT
Pub. No.: |
WO2015/088893 |
PCT
Pub. Date: |
June 18, 2015 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20160311755 A1 |
Oct 27, 2016 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
61913982 |
Dec 10, 2013 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07C
69/593 (20130101); C09D 5/086 (20130101); C10M
129/74 (20130101); C07C 215/40 (20130101); C10L
1/191 (20130101); C07C 69/40 (20130101); C07C
211/63 (20130101); C07C 217/08 (20130101); C10M
133/46 (20130101); C23F 11/128 (20130101); C07C
69/75 (20130101); C10M 129/76 (20130101); B05D
7/00 (20130101); C10M 133/08 (20130101); C23F
11/143 (20130101); C10M 133/06 (20130101); C23F
11/10 (20130101); C10L 10/04 (20130101); C07C
2601/14 (20170501); C10M 2215/02 (20130101); C10M
2207/282 (20130101); C10M 2207/289 (20130101); C10M
2215/04 (20130101); C10N 2040/25 (20130101); C10M
2215/042 (20130101); C10M 2207/401 (20130101); C10M
2215/224 (20130101); C10N 2030/12 (20130101); C10M
2207/283 (20130101) |
Current International
Class: |
C07C
69/75 (20060101); C09D 5/08 (20060101); C07C
217/08 (20060101); C10L 10/04 (20060101); C23F
11/10 (20060101); C07C 69/593 (20060101); C07C
69/40 (20060101); C23F 11/12 (20060101); B05D
7/00 (20060101); C23F 11/14 (20060101); C07C
211/63 (20060101); C07C 215/40 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
WO 2005/071050 |
|
Aug 2005 |
|
WO |
|
Other References
Lubrizol, et al., "VEG-ESTER.TM. GY-300 Additive Technology,"
Metalworking Fluid Additives, pp. 1-4, downloaded on Sep. 19, 2016.
cited by applicant.
|
Primary Examiner: Green; Anthony J
Attorney, Agent or Firm: Fay Sharpe LLP
Parent Case Text
This application claims the benefit of PCT/US2014/068707, filed
Dec. 5, 2014, and U.S. Provisional Application No. 61/913,982,
filed Dec. 10, 2013, from which the PCT application claims
priority, the disclosures of which are incorporated herein by
reference in their entireties.
Claims
What is claimed is:
1. A corrosion-inhibiting composition comprising a diluent and a
mixture of organic salts of half ester-half acids having the
general structure of STRUCTURE (1) at a total concentration of from
0.01-30 wt. % of the composition: ##STR00017## where: n is from
0-2; G is a glyceride residue comprising a mixture of: ##STR00018##
each FA is a straight-chain fatty acyl residue having from 4 to 24
carbon atoms and from 0 to 3 double bonds in the carbon chain;
R.sub.1 and R.sub.2 are independently selected from hydrogen,
straight-chain or branched alkyl or alkenyl groups having from 1-18
carbon atoms or where R.sub.1 and R.sub.2 together with the two
carbons atoms to which they attach and the --(CH.sub.2).sub.n--
group form a cyclic structure having at least 5 carbon atoms; and A
is a neutralizing group which comprises an ammonium ion or a
protonated organic base selected from the group consisting of
protonated amines, alkylamines, alkanolamines, imidazoles,
alkylimidazoles, and combinations thereof.
2. The composition of claim 1, wherein n is 0.
3. The composition of claim 1, wherein the mixture of organic salts
of half ester-half acids having the general structure of STRUCTURE
(1) is at a total concentration of at least 1 wt. % of the
composition.
4. The composition of claim 1, wherein the mixture of organic salts
of half ester-half acids having the general structure of STRUCTURE
(1) is at a total concentration of up to 10 wt. % of the
composition.
5. The composition of claim 1, wherein the diluent is selected from
water, volatile organic solvents, oils, and combinations
thereof.
6. The composition of claim 5, wherein the volatile organic solvent
is selected from aliphatic and aromatic hydrocarbons, alcohols,
glycols, toluene, terpenoids, terpenes, esters, ethers, acetals,
polar aprotic solvents, ketones, and derivatives and combinations
thereof.
7. The composition of claim 1, wherein the composition is in the
form of an emulsion.
8. The composition of claim 1, wherein the diluent is present in
the composition at a total concentration of at least 50 wt. %.
9. The composition of claim 1, wherein at least some of the fatty
acyl residues are derived from a vegetable oil.
10. The composition of claim 9, wherein the vegetable oil has less
than 20 wt. % saturated fatty acids.
11. The composition of claim 1, wherein the fatty acyl residues
have an average of greater than 14 carbon atoms.
12. The composition of claim 1, wherein the protonated organic base
comprises a protonated amine.
13. The composition of claim 1, wherein the protonated organic base
is selected from the group consisting of 2-(2-aminoethoxy)ethanol;
5-amino-1-pentanol; 3-amino-1-propanol; 2-(2-aminoethoxy)ethanol;
N,N-diethylethanolamine; 3-dimethylamino-1-propylamine;
N,N-dimethylethanolamine; monoethanolamine; 2-ethylhexylamine;
imidazole; 3-isododecyloxy-1-propylamine; 3-methoxypropylamine;
1-methylimidazole; 2-methylimidazole; tributylamine;
triethanolamine; triisopropanolamine; a mixture of
C.sub.10-C.sub.15 tert-alkyl primary amines; and combinations
thereof.
14. The composition of claim 1, wherein an average number of FA
groups per glyceride residue G in the mixture is at least 1.
15. The composition of claim 1, wherein an average molecular weight
of organic salts in the mixture is less than 1250 g/mole.
16. The composition of claim 1, wherein when n is 0, at least one
of R.sub.1 and R.sub.2 is not hydrogen.
17. A corrosion-inhibiting composition comprising a diluent and a
mixture of organic salts of half ester-half acids having the
general structure of STRUCTURE (1) at a total concentration of from
0.01-30 wt. % of the composition: ##STR00019## where: n is from
0-2; G is a glyceride residue comprising a mixture of: ##STR00020##
each FA is a straight-chain fatty acyl residue having from 4 to 24
carbon atoms and from 0 to 3 double bonds in the carbon chain,
wherein at least some of the fatty acyl residues are derived from
an unhydrogenated vegetable oil; R.sub.1 and R.sub.2 are
independently selected from hydrogen, straight-chain or branched
alkyl or alkenyl groups having from 1-18 carbon atoms or where
R.sub.1 and R.sub.2 together with the two carbons atoms to which
they attach and the --(CH.sub.2).sub.n-- group form a cyclic
structure having at least 5 carbon atoms; and A is a neutralizing
group.
18. The composition of claim 17, wherein the neutralizing group
comprises at least one of a protonated organic base, a metal
cation, and an ammonium ion.
19. The composition of claim 18, wherein the neutralizing group
comprises a protonated organic base selected from the group
consisting of protonated amines, alkylamines, alkanolamines,
imidazoles, alkylimidazoles; and combinations thereof.
20. A method of inhibiting corrosion of a metallic surface in
contact with a corrosive environment, the method comprising:
contacting the surface with a corrosion-inhibiting composition
comprising a diluent and a mixture of organic salts of half
ester-half acids having the general structure of STRUCTURE (1) at a
total concentration of from 0.01-30 wt. % of the composition:
##STR00021## where: n is from 0-2; G is a glyceride residue
comprising a mixture of: ##STR00022## each FA is a straight-chain
fatty acyl residue having from 4 to 24 carbon atoms and from 0 to 3
double bonds in the carbon chain; R.sub.1 and R.sub.2 are
independently selected from hydrogen, straight-chain or branched
alkyl or alkenyl groups having from 1-18 carbon atoms or where
R.sub.1 and R.sub.2 together with the two carbons atoms to which
they attach and the --(CH.sub.2).sub.n-- group form a cyclic
structure having at least 5 carbon atoms; and A is a neutralizing
group.
21. A method for forming a corrosion-inhibiting composition
comprising: reacting a triglyceride of the general structure:
##STR00023## with glycerin in the presence of a transesterification
catalyst to form a glyceride mixture, where each FA is a
straight-chain fatty acyl residue having from 4 to 24 carbon atoms
and from 0 to 3 double bonds in the carbon chain; reacting the
glyceride mixture with a cyclic carboxylic acid anhydride; with a
neutralizing base, neutralizing the product of the reaction of the
glyceride mixture with the cyclic carboxylic acid anhydride; and
combining the neutralized reaction product with a diluent to form
the corrosion-inhibiting composition, wherein the neutralized
reaction product is at a total concentration of from 0.01-30 wt. %
of the composition.
22. The method of claim 21, wherein the cyclic carboxylic acid
anhydride has the structure general structure of STRUCTURE (3):
##STR00024## where R.sub.1 and R.sub.2 are independently selected
from hydrogen, straight-chain or branched alkyl or alkenyl groups
having from 1-18 carbon atoms or where R.sub.1 and R.sub.2 together
form a cyclic structure having at least 5 carbon atoms.
23. A mixture of organic salts of half ester-half acids having the
general structure of STRUCTURE (1): ##STR00025## where: n is from
0-2; G is a glyceride residue comprising a mixture of: ##STR00026##
each FA is a straight-chain fatty acyl residue having from 4 to 24
carbon atoms and from 0 to 3 double bonds in the carbon chain;
R.sub.1 and R.sub.2 are independently selected from hydrogen,
straight-chain or branched alkyl or alkenyl groups having from 1-18
carbon atoms or where R.sub.1 and R.sub.2 together with the two
carbons atoms to which they attach and the --(CH.sub.2).sub.n--
group form a cyclic structure having at least 5 carbon atoms; and A
is a neutralizing group, which comprises an ammonium ion or a
protonated organic base selected from the group consisting of
protonated amines, alkylamines, alkanolamines, imidazoles,
alkylimidazoles; and combinations thereof.
24. A corrosion-inhibiting composition comprising: an emulsion
comprising: at least 70 wt. % of a diluent comprising at least one
of water and an organic solvent; and 0.01-30 wt. % of a mixture of
organic salts of half ester-half acids having the general structure
of STRUCTURE (1) at a total concentration of from 0.01-30 wt. % of
the composition: ##STR00027## where: n is from 0-2; G is a
glyceride residue comprising a mixture of: ##STR00028## each FA is
a straight-chain fatty acyl residue having from 4 to 24 carbon
atoms and from 0 to 3 double bonds in the carbon chain; R.sub.1 and
R.sub.2 are independently selected from hydrogen, straight-chain or
branched alkyl or alkenyl groups having from 1-18 carbon atoms or
where R.sub.1 and R.sub.2 together with the two carbons atoms to
which they attach and the --(CH.sub.2).sub.n-- group form a cyclic
structure having at least 5 carbon atoms; and A is a neutralizing
group.
Description
BACKGROUND
The exemplary embodiment relates to corrosion inhibitors based on
organic salts of glyceride-cyclic carboxylic acid anhydride adducts
and to methods of inhibiting corrosion using these corrosion
inhibitors.
Corrosion inhibitors (sometimes called rust preventatives) are
widely used for inhibiting atmospheric corrosion of bare metal on
finished or freshly-milled metallic articles. Corrosion inhibitors
in current use are often derived from petroleum waxes. These waxes
are becoming scarce due to operational changes in many petroleum
refineries. Petroleum-derived waxes are also considered
non-renewable since they take millions of years to form. One class
of corrosion inhibitors includes high-molecular weight petroleum
waxes that have been partially oxidized in the presence of various
metal catalysts to produce a mixture of waxy or oily organic acids.
The salts of these organic acids exhibit affinity for metal
surfaces, forming a hydrophobic barrier that inhibits
corrosion.
It would be desirable if corrosion inhibitors that perform as well
as petroleum-derived corrosion inhibitors could be derived from
renewable resources, such as animal or vegetable matter.
BRIEF DESCRIPTION
In accordance with one aspect of the exemplary embodiment a
corrosion inhibiting composition includes a diluent and a mixture
of organic salts of half ester-half acids having the general
structure of STRUCTURE (1) at a total concentration of from 0.01-30
wt. % of the composition:
##STR00001## where: n is from 0-2; G is a glyceride residue
comprising a mixture of:
##STR00002## each FA is a straight-chain fatty acyl residue having
from 4 to 24 carbon atoms and from 0 to 3 double bonds in the
carbon chain; R.sub.1 and R.sub.2 are independently selected from
hydrogen, straight-chain or branched alkyl or alkenyl groups having
from 1-18 (or 8-18) carbon atoms or where R.sub.1 and R.sub.2
together with the two carbons atoms to which they attach and the
--(CH.sub.2).sub.n-- group form a cyclic structure having at least
5 carbon atoms (or 5-18 carbon atoms); and A is a neutralizing
group; in one embodiment R.sub.1 and R.sub.2 may be independently
selected from straight chain or branched alkyl or alkenyl groups
having 8-18 carbon atoms where two ends of the carbon chain form a
cyclic structure.
In accordance with another aspect of the exemplary embodiment a
method for forming a corrosion inhibiting composition includes
reacting a triglyceride of the general structure:
##STR00003##
with glycerin in the presence of a transesterification catalyst to
form a glyceride mixture, where each FA is a straight-chain fatty
acyl residue having from 4 to 24 carbon atoms and from 0 to 3
double bonds in the carbon chain, and reacting the glyceride
mixture with a cyclic carboxylic acid anhydride. The product of the
reaction of the glyceride mixture with the cyclic carboxylic acid
anhydride is neutralized with a neutralizing base. The neutralized
reaction product is combined with a diluent to form the corrosion
inhibiting composition. The neutralized reaction product is at a
total concentration of from 0.01-30 wt. % of the composition.
In another embodiment, a mixture of organic salts of half
ester-half acids having the general structure of STRUCTURE (1) is
provided.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE shows film thickness of corrosion inhibitor films vs.
emulsion treat rate.
DETAILED DESCRIPTION
Aspects of the exemplary embodiment relate to half-ester/half-acid
mixtures derived from glycerides, such as renewable vegetable or
animal triglycerides, that when salted with a variety of organic
and inorganic bases provide corrosion inhibiting compounds that can
exhibit superior performance to conventional petroleum-derived
corrosion inhibitors. Also disclosed is a composition for
inhibiting corrosion which incorporates the mixture of half
ester-half acid organic salts, a diluent, and optionally one or
more adjuvants. Also disclosed is a method of providing corrosion
inhibition to a metallic substrate with the composition.
The corrosion inhibiting composition includes at least one and
generally a mixture of organic salts of half ester-half acids
having the general structure of STRUCTURE (1):
##STR00004##
where n may be from 0-2.
In particular, when n=0, the mixtures of organic salts of half
ester-half acids have the general structure of STRUCTURE (2):
##STR00005##
where G is a glyceride residue comprising (or consisting
essentially of) a mixture of:
##STR00006##
where: "- *" indicates the oxygen that attaches the glyceride
residue to the rest of STRUCTURE (1) or STRUCTURE (2),
each FA is a straight-chain fatty acyl residue having from 4 to 24
carbon atoms and which may have from 0 to 3 double bonds in the
carbon chain,
R.sub.1 and R.sub.2 are independently selected from hydrogen,
straight-chain or branched alkyl or alkenyl groups having from 1-18
(or 8-18) carbon atoms or where R.sub.1 and R.sub.2 together with
the two carbons atoms to which they attach and the
--(CH.sub.2).sub.n-- group form a cyclic structure having at least
5 carbon atoms (or 5-18 carbon atoms); and
A+ is a neutralizing group, such as a protonated organic base or a
metal cation derived from a neutralizing base.
In some embodiments, the corrosion inhibiting composition described
herein includes at least one and generally a mixture of organic
salts of half ester-half acids having the general structure of
STRUCTURE (1), as described above, where R.sub.1 and R.sub.2 cannot
both be hydrogen when n is 0. In such embodiments at least one of
R.sub.1 and R.sub.2 is/are independently selected from a
straight-chain or branched alkyl or alkenyl group having from 1-18
carbon atoms or where R.sub.1 and R.sub.2 together with the two
carbons atoms to which they attach and the --(CH.sub.2).sub.n--
group form a cyclic structure having at least 5 carbon atoms carbon
atoms. In some embodiments at least one of R.sub.1 or R.sub.2 is a
straight-chain or branched alkyl or alkenyl group having from 8-18
carbon atoms.
In some embodiments, the corrosion inhibiting composition described
herein includes at least one and generally a mixture of organic
salts of half ester-half acids having the general structure of
STRUCTURE (1), as described above, where n is 0, R.sub.1 and
R.sub.2 together form a cyclic structure that creates a 6 membered
ring in the overall structure, and which may further include one or
more alkyl substituent groups linked to the ring, or which may be
free of any further substituent group. In some embodiments the
structure includes a single alkyl substituent group, and in some of
these embodiments that alkyl substituent group may be a methyl
group. In such embodiments the described corrosion inhibiting
composition includes at least one and generally a mixture of
organic salts of half ester-half acids having the general structure
of STRUCTURE (1A) and/or STRUCTURE (1B):
##STR00007##
where: G is a glyceride residue comprising (or consisting
essentially of) a mixture of:
##STR00008##
where: each FA is a straight-chain fatty acyl residue having from 4
to 24 carbon atoms and which may have from 0 to 3 double bonds in
the carbon chain; and
A+ is a neutralizing group, such as a protonated organic base or a
metal cation derived from a neutralizing base.
By "consisting essentially of," it is meant that compounds
containing residues other than G (e.g., derived from triglyceride
and/or glycerol) account for less than 10 wt. % of the mixture.
The exemplary compounds are monomers, where there is only one
glyceride residue per molecule and only one acid group per
molecule, although small amounts of dimers and higher polymers
(e.g., in total, less than 20%, or less than 10%, or less than 2%
by weight of the mixture) may be present. An average molecular
weight of the organic salts of STRUCTURE (1) and/or (2) in the
mixture may be up to 1250 g/mole.
The glyceride G may be derived from renewable vegetable or animal
triglycerides.
The fatty acyl resides FA may contain a range of carbon chain
lengths, which maybe predominantly (e.g., at least 50% or at least
60%, or at least 70%) even-numbered, e.g., ranging from C.sub.4 to
C.sub.24. In one embodiment, the fatty acyl residues are
predominantly (e.g., at least 50% or at least 60%, or at least 70%)
in the range C.sub.12 to C.sub.24 or in the range C.sub.16 to
C.sub.20. In one specific embodiment, C.sub.18 is a major component
(e.g., at least 50% or at least 60% of the FA are C.sub.18). In one
embodiment, a proportion of fatty acyl resides having 3 double
bonds (such as linolenic acid) is less than 50%, such as less than
20% or less than 10%. For some applications, high degrees of
unsaturation, i.e., glycerides having a high proportion of
polyunsaturated fatty acid residues such as linolenic acid are
undesirable, owing to the higher oxidative instability that may
result.
The fatty acyl residues have the general formula O--C(O)--R.sub.5
where R.sub.5 is a carbon chain having a number of carbon atoms
predominantly in the range C.sub.11 to C.sub.23, e.g.,
predominantly in the range C.sub.15 to C.sub.19. Example fatty
acids from which the fatty acyl residues may be derived include
saturated fatty acids, such as hexanoic, heptanoic, octanoic,
nonanoic, decanoic, undecanoic, tridecanoic, tetradecanoic,
pentadecanoic, hexadecanoic, heptadecanoic, octadecanoic,
nonadecanoic, eicosanoic, heneicosanoic, deocosanoic, tricosanoic,
tetracosanoic, pentacosanoic, hexacosanoic, heptacosanoic,
octacosanoic, and nonacosanoic acids, and unsaturated fatty acids,
having at least one double bond, such as myristoleic, palmitoleic,
sapienic, oleic, elaidic, vaccenic, linoleic, linoelaidic,
.alpha.-linolenic, arachidonic, eicosapentaenoic, erucic, and
docosahexaenoic acids, combinations thereof, and the like.
In one embodiment, an average number of FA groups per glyceride
residue G in the mixture is at least 1 or at least 1.2, or at least
1.4.
In one embodiment the neutralizing group A+ is a protonated organic
base. Example protonated organic bases include nitrogen-containing
bases, such as protonated amines, alkylamines, alkanolamines,
imidazoles, alkylimidazoles, and the like.
In another embodiment, the neutralizing group A+ is a metal ion
such as a group I or Group II metal, such as sodium, potassium,
calcium, barium, combination thereof, or the like.
In the compounds of STRUCTURE(1) or (2), the negatively charged
carboxylate group is attracted to a metal surface while the rest of
the molecule is very hydrophobic and repels water to retard
corrosion significantly.
The groups FA, R.sub.1, R.sub.2, and A in STRUCTURE (1) or (2) may
be selected to provide organic salts of glyceride-cyclic carboxylic
acid anhydride adducts which give significantly improved rust
prevention as compared to traditional corrosion inhibitory
compounds based on partial oxidation of petroleum waxes.
The mixture of organic salts of half ester-half acids according to
STRUCTURES (1) and (2) may be solid or liquid at ambient
temperature (25.degree. C.). In one embodiment, the salt mixture is
a liquid having a kinematic viscosity of less than 5000 mPas, such
as less than 1000 mPas at 40.degree. C., as measured according to
ASTM D455. In some embodiments, the salt mixture may have a pour
point, as measured according to ASTM D97-12, of 20.degree. C. or
less, such as 10.degree. C. or less.
Method of Preparation of the Compounds of STRUCTURE (1) or (2)
The exemplary half ester-half acid salts can be produced by a
method which includes three sequential steps as follows:
First, a glyceride mixture is formed by reacting a triglyceride of
the general structure:
##STR00009## where FA is defined as above, with glycerin in the
presence of a transesterification catalyst.
In a second step, the glyceride mixture is reacted with a cyclic
carboxylic acid anhydride having the structure general structure of
STRUCTURE (3):
##STR00010##
where R.sub.1 and R.sub.2 are as defined above.
The product of this reaction is a half ester-half acid having the
structure of STRUCTURE (4):
##STR00011##
where G is a glyceride residue as defined above, and R.sub.1 and
R.sub.2 are as defined previously.
To form compounds of STRUCTURE (1) where n is 1 or more, a cyclic
carboxylic acid anhydride with a 6 or 7 membered ring is used in
place of STRUCTURE (3).
A third step involves neutralizing the reaction product of the
second step (the half ester-half acid) with an organic base or
other neutralizing base. Further details of the three steps are now
provided.
1. Preparation of Glyceride Mixture
Examples of methods for preparing glyceride mixtures suitable for
use herein are provided in U.S. Pat. Nos. 4,263,216 and
7,081,542.
In one embodiment, the preparation involves transesterification of
a triglyceride with glycerin in the presence of an alkyltin
transesterification catalyst at elevated temperatures.
The resulting glyceride mixture contains the following species, in
addition to unreacted triglyceride and glycerin:
##STR00012##
where each FA is a fatty acyl residue from the starting
triglyceride, as described above.
Examples of suitable triglycerides useful herein include vegetable
and animal-derived triglycerides, such as those contained in almond
oil, canola oil, cocoa butter, cocoa oil, coconut oil, corn oil,
cottonseed oil, flax seed oil, linseed oil, neem oil, olive oil,
palm oil, palm kernel oil, palm stearin, palm butter, peanut oil,
rapeseed oil, rice bran oil, safflower oil, sesame oil, soybean
oil, sunflower seed oil, and tung oil, and animal-derived
triglycerides such as beef tallow, butter oil, butterfat, cod liver
oil, herring/fish oil, lanolin oil, lard, mutton tallow, neatsfoot
oil, and sardine oil. Partially or totally hydrogenated derivatives
of these oils and fats may also be employed in order to make
higher-melting, waxier analogs. In one embodiment, the vegetable
oil is an unhydrogenated vegetable oil and/or has less than 20 wt.
% saturated fatty acids. Synthetically-produced triglycerides are
also contemplated.
Example fatty acyl groups FA in such triglycerides may include,
among others, those which correspond to unsaturated fatty acids,
such as myristoleic acid, palmitoleic acid, sapienic acid, oleic
acid, elaidic acid, vaccenic acid, linoleic acid, linoelaidic acid,
.alpha.-linolenic acid, arachidonic acid, eicosapentaenoic acid,
erucic acid, and docosahexaenoic acid, and saturated fatty acids,
such as caprylic acid; capric acid; lauric acid, myristic acid,
palmitic acid; stearic acid, arachidic acid, behenic acid,
lignoceric acid, cerotic acid, isostearic acid, gadoleic acid, and
combinations thereof.
As an example, the major unsaturated fatty acids in soybean oil
triglycerides are approximately: alpha-linolenic acid (7-10%),
linoleic acid (51%), and oleic acid (23%). It also contains the
saturated fatty acids, stearic acid (4%), and palmitic acid
(10%).
The second reactant used in the preparation of the glyceride
mixture is glycerin. The glycerin may be natural or synthetically
derived, and the purity need not be high as long as the glycerin is
not significantly contaminated with water. A suitable water content
of the glycerin is 0.2 wt. % or less.
The molar ratio of triglyceride to glycerin may vary, depending on
the desired average number of fatty acyl groups per molecule in the
final product. Molar ratios of triglyceride to glycerin from about
3:1 to about 1:2 are exemplary, with a molar ratio of 2.5:1 to 1:1,
e.g., about 2:1, being suited to providing a mixture with
relatively low amounts of residual triglyceride. At all ratios,
some unreacted triglyceride and/or glycerin will invariably be
present at the end of the transesterification reaction. These
unreacted materials are generally undesirable impurities that may
adversely impact the performance of the final products if their
amounts are too high. The amount of unreacted triglyceride in the
glyceride mixture increases as the molar ratio of triglyceride to
glycerin increases. Conversely, the amount of unreacted glycerin in
the glyceride mixture increases as the ratio of triglyceride to
glycerin decreases.
A transesterification catalyst may be employed in order to
accelerate the reaction between the triglyceride and glycerin
and/or allow a lower temperature to be employed.
Transesterification catalysts are well known and many are
commercially available. Examples include acids (e.g., sulfuric
acid, phosphoric acid, sulfonic acids), bases (e.g., alkali metal
and alkaline earth metal oxides and hydroxides such as potassium
hydroxide, lithium hydroxide), dry sodium or potassium salts of
alcohols (sodium or potassium alkoxides), organotin compounds, and
titanium compounds. Example organotin catalysts include
tetrabutyitin, trioctyitin ethoxide, dibutyltin dimethoxide,
dibutyltin dihydride, dibutyltin bis(2-ethylhexanoate), dibutyltin
maleate, bis(tributyltin) oxide, bis(dibutylmethoxytin) oxide, and
dibutyl tin dilaurate. Organic tin catalysts are available, for
example, from PMC Organometallix under the trade name Fascat.RTM.,
such as butyltin tris(2-ethylhexanoate), available as Fascat.RTM.
4102, dibutyltin dilaurate, available as Fascat.RTM. 4202, as well
as tin(II) bis(2-ethylhexanoate), butylstannoic acid, and
dibutyltin oxide. Example organic titanate catalysts are
commercially available from Dorf Ketal under the trade name
Tyzor.RTM.. These include tetraethyl titanate, tetraisopropyl
titanate, tetra-n-propyl titanate, tetra-n-butyl titanate,
tetra-2-ethylhexyl titanate, titanium acetylacetonate, and the
like. In the case of sodium or potassium hydroxide catalysts,
dehydration of the reaction mixture is usually required. Litharge
(a lead oxide) has also been widely used as a catalyst. In one
embodiment, the transesterification catalyst includes an alkyltin
compound, such as dibutyltin dilaurate.
The level of the transesterification catalyst can be from about
0.001 to 0.2 wt. % of the total reactant mixture, such as at least
0.01 wt. %.
The reaction temperature and reaction time in this step of the
process may be suitably selected such that the reactants fully
equilibrate to form the thermodynamically stable glyceride mixture.
As an example, the transesterification reaction can be performed by
reacting the triglyceride with the glycerin for a period of about
2-16 hours at a temperature of about 180.degree. C. The
triglyceride and glycerin may be combined as liquids (the
triglyceride being pre-melted if it is a solid at room
temperature), and heated to about 180.degree. C. with continuous
agitation. The catalyst may be added after the reactants are up to
temperature. Heating at about 180.degree. C. is continued for about
8 hours, during which time the separate glycerin phase disappears.
A blanket of nitrogen or other inert gas can be maintained over the
reaction mixture throughout the process in order to prevent trace
oxidation of the glyceride mixture resulting in higher color.
The fatty acyl residues tend to reach their natural equilibrium
distribution on the various available alcohol sites in the reaction
mixture. The resulting equilibrium mixture is generally not a
statistically random distribution of the fatty acyl groups on the
glycerin oxygen atoms because thermodynamically the acyl groups
preferentially locate on the two primary glycerin oxygen atoms
rather than the central secondary oxygen. The fatty acyl residues
thus predominantly reside on the primary alcohol sites. Thus the
.alpha.-monoglyceride and 1,3-diglyceride tend to have
significantly higher concentrations in the thermodynamically stable
glyceride mixture than would be expected based on a statistically
random distribution. For example, it has been observed that in a
mixture that has on average two fatty acyl groups per glycerin, the
proportion of 1,3-diglyceride may be as high as 80% or more if the
mixture is fully equilibrated in the presence of a
transesterification catalyst, whereas the statistically calculated
molar percentage of 1,3-diglyceride in a completely random mixture
is only about 15% (see, for example, U.S. Pat. No. 4,263,216).
The glyceride mixture thus obtained is cooled from the reaction
temperature and may be used directly without purification. Knowing
the average molecular weight of the starting triglyceride (for
example by calculation from the saponification value), the average
molecular weight per free hydroxyl group in the glyceride mixture
may be readily calculated. This calculated weight per hydroxyl may
be used when determining the molar ratio of reactants for the next
step of the process.
The exemplary glyceride mixture thus obtained has from about 0.75
to about 2.0 free hydroxyl groups, on average, per molecule, with
an average of 1.0 being particularly suitable.
2. Reaction of Glyceride Mixture with Cyclic Carboxylic Acid
Anhydride
The second step involves the reaction between a glyceride mixture,
as described above, and a cyclic carboxylic acid anhydride having
the general structure:
##STR00013##
where R.sub.1 and R.sub.2 are independently selected from:
hydrogen; straight-chain or branched alkyl groups having from 1-18
carbon atoms each or together (e.g., together with the carbon atoms
to which they are attached) form a cyclic structure including a
ring containing at least 5 carbon atoms. Specific examples of these
cyclic carboxylic acid anhydrides include succinic anhydride,
hexahydrophthalic anhydride (HHPA), methylhexahydrophthalic
anhydride (MHHPA), octenylsuccinic anhydride (OSA),
octadecenylsuccinic anhydride (ODSA), and combinations thereof.
In one embodiment, at least one of R.sub.1 and R.sub.2 is not H. In
one embodiment, R.sub.1 and R.sub.2 form a cyclic structure, as in
hexahydrophthalic anhydride and methylhexahydrophthalic anhydride.
In one embodiment, where R.sub.1 and R.sub.2 form a cyclic
structure, the ring formed is saturated.
While five-membered ring cyclic anhydrides are more economical than
six-membered and larger cyclic anhydrides, it is also contemplated
that anhydrides having additional carbon atoms in the anhydride
ring may be employed.
Although maleic anhydride and phthalic anhydride may be employed in
this step of the process, these cyclic carboxylic acid anhydrides
may be undesirable due to toxicity concerns. Fine filamentous
crystals of these specific anhydrides can also form in the vapor
space of the reaction vessel. In the case of maleic anhydride, the
carbon-carbon double bond may also be undesirable in the final
product.
In one embodiment, a mixture of two or more cyclic anhydrides is
employed to impart different properties to the corrosion inhibitor.
The smallest, most flexible anhydride is succinic anhydride. HHPA
and MHHPA introduce rigidity near the acid group because of the
ring structure. Alkenyl succinic anhydrides, such as OSA and ODSA,
introduce a third fatty tail, the length of which can be the same
as or different from the length of the two tails from the
glyceride.
An exemplary molar ratio of the cyclic carboxylic acid anhydride to
the free hydroxyl groups in the glyceride mixture is from 0.8 to
1.0, such as a ratio of about 0.9.
The cyclic carboxylic acid anhydride is suitably added to the
glyceride mixture at the about lowest temperature at which the
glyceride mixture is completely melted. The mixture of the two
reagents is then heated to a sufficient temperature and for
sufficient time such that substantially complete reaction between
the cyclic anhydride and free hydroxyl groups of the glyceride
mixture occurs. A final reaction temperature of about
120-130.degree. C. is generally sufficient for most cyclic
anhydrides. At these reaction temperatures, the reaction is usually
substantially complete after about four to five hours, however
longer reaction times may be employed in some cases. No catalyst is
required for this reaction. The cyclic anhydride is thus converted
into a half acid/half ester type structure of the form shown in
STRUCTURE (4) in which the glyceride residue G is connected through
one of the oxygen atoms that was a free OH group in the glyceride
mixture above.
During this reaction the removal of water from the reaction mixture
is generally to be avoided. Water removal can be avoided using a
condenser to return water vapor to the reaction and/or by water
addition. If water is removed, this indicates that a second
esterification is occurring between the free carboxylic acid in the
structure above and a free hydroxyl group of the glyceride mixture.
This is an undesired reaction that produces a di-ester having the
structure:
##STR00014##
where G is defined as above.
In one embodiment, the reaction between the glyceride mixture and
the cyclic carboxylic acid anhydride is monitored by periodic
measurement of the acid number of the reaction mixture (i.e.,
milligrams of KOH required to titrate one gram of the reaction
mixture to a neutral pH). Initially, each mole of cyclic carboxylic
acid anhydride in the reaction mixture may be considered as two
moles of acid. The glyceride mixture contributes negligible
acidity. Theoretically, the acid number of the reaction mixture
should fall to exactly one half of this initial calculated value if
all of the cyclic carboxylic acid anhydride reacts as desired. In
practice, the acid number rarely reaches more than about 90-95% of
this theoretical value, at which point the reaction can be deemed
to be substantially complete. In another embodiment, the reaction
is monitored by infrared spectroscopy. The cyclic carboxylic acid
anhydrides exhibit strong characteristic twin absorbance bands at
about 1860 and 1775 cm-1. These bands continuously diminish as the
reaction progresses.
This reaction can be conducted by combining the glyceride mixture
and cyclic carboxylic acid anhydride at a temperature at which the
glyceride is liquid and then slowly warming the mixture to a
temperature of 120 to 140.degree. C. for a period of about 4-8
hours, while ensuring that that water is not allowed to distill
from the reaction mixture during this time. In this step, a molar
ratio of cyclic carboxylic acid anhydride to free hydroxyl groups
in the glyceride mixture can be from about 0.8:1 to about
1.0:1.
3. Neutralization of Glyceride/Cyclic Carboxylic Acid Anhydride
Adducts
The half acid/half ester adduct resulting from the reaction between
a glyceride mixture and a cyclic carboxylic acid anhydride produced
in step 2 is neutralized with an organic or inorganic base to
produce the mixture of STRUCTURE (1) or (2). Organic bases useful
for this step include compounds containing a combination of the
elements carbon, hydrogen, nitrogen, oxygen, sulfur, and/or
phosphorus and having sufficient basicity such that the base
deprotonates the carboxylic acid residue of the half acid/half
ester adduct.
The neutralization reaction may be conducted at a relatively low
temperature, but warm enough such that the half ester-half acid
mixture is liquid. The neutralization reaction is exothermic, so in
general, no additional heating of the reactants is required in this
step. For solid bases such as imidazole, however, mild heating may
beneficially accelerate the neutralization process by increasing
the rate of dissolution of the solid base into the reaction
mixture. In this step, a molar ratio of organic base to the acid
groups in the half acid/half ester adducts can be about 0.8 to 1.2,
such as a ratio of about 0.9 to 1.1, or about 0.9 to 1.0. Excess
organic base can result in increased odor in the final product if
the base is an odoriferous volatile amine.
Representative organic bases include primary, secondary, and
tertiary amines and diamines. Exemplary amines may have linear,
branched, or cyclic alkyl groups. The number of carbons in the
alkyl groups can be from 1 to about 18. Other organic bases include
nitrogen-containing heterocycles such as imidazole and
alkyl-substituted imidazoles; pyridine or substituted pyridines;
morpholine, piperazine, piperidine, and their substituted
derivatives; alkanolamines and alkylalkanolamines; ether amines,
combinations thereof, and the like.
Examples of organic bases useful for the neutralization step
include: primary alkylamines, such as methylamine, ethylamine,
n-propylamine, n-butylamine, n-hexylamine, n-octylamine,
2-ethylhexylamine, benzylamine, 2-phenylethylamine, cocoamine,
oleylamine, and tridecylamine (CAS#86089-17-0); secondary and
tertiary alkylamines such as isopropylamine, sec-butylamine,
tert-butylamine, and tributylamine, cyclopentylamine,
cyclohexylamine, and 1-phenylethylamine; dialkylamines, such as
dimethylamine, diethylamine, dipropylamine, diisopropylamine,
dibutylamine, dicyclohexylamine, di-(2-ethyhexyl)amine,
dihexylamine, ethylbutylamine, N-ethylcyclohexylamine, and
N-methylcyclohexylamine; cycloalkylamines, such as piperidine,
N-methylpiperidine, N-ethylpiperidine, pyrrolidine,
N-methylpyrrolidine, and N-ethylpyrrolidine; aliphatic alicylclic
and aromatic diamines, such as 3-dimethylamino-1-propylamine;
alkanolamines such as 2-aminoethanol (monoethanolamine),
diethanolamine, triethanolamine, monoisopropanolamine,
diisopropanolamine, triisopropanolamine, 2-(2-aminoethoxy)ethanol,
5-aminopentanol, 3-aminopropanol, 2-amino-2-methylpropanol,
2-dimethylamino-2-methylpropanol, 2-amino-2-methyl-1,3-propanediol,
2-amino-2-ethyl-1,3-propanediol,
2-amino-2-hydroxymethyl-1,3-propanediol, morpholine, and
N-(2-hydroxyethyl)morpholine; alkylalkanolamines such as
N-methylethanolamine, N-methyldiethanolamine,
N-ethyldiethanolamine, N,N-dimethylethanolamine,
N,N-diethylethanolamine, N-butylethanolamine,
N-butyldiethanolamine, N-octylethanolamine, and
N-octyldiethanolamine; heterocycles such as imidazole,
1-methylimidazole, 2-methylimidazole, 1-ethylimidazole,
2-ethylimidazole, pyridine, 2-methylpyridine, 3-methylpyridine,
4-methylpyridine; quaternary ammonium hydroxides such as
tetramethylammonium hydroxide, tetraethylammonium hydroxide, and
tetrabutylammonium hydroxide; ether amines, such as
3-(isotridecyloxy)propylamine; and polyfunctional materials such as
guanidine, tetramethylguanidine,
1,8-diazabicyclo[5.4.0]undec-7-ene,
1,5-diazabicyclo[4.3.0]non-5-ene,
tert-butylimino-tris(dimethylamino)phosphorane; combinations
thereof, and the like.
Inorganic neutralizing bases include ammonia and oxides and
hydroxides of Group I and II metals, such as sodium hydroxide and
calcium oxide (lime). The neutralizing base may be selected to
provide desirable solubility in the selected diluent. By way of
example, a hydrophobic amine, such as 2-ethylhexylamine, may be
selected to provide a salt that is soluble in an organic solvent. A
water soluble amine, such as 3-amino-1-propanol, may be selected to
provide a salt that is water emulsifiable. Calcium oxide or
hydroxide may be selected to provide an oil-soluble and/or
solvent-soluble, thixotropic composition.
The resultant salts are suitably homogeneous materials when molten,
and may be liquids at room temperature. Slurries, gels, partial
solids, and two-phase liquids are generally undesirable physical
forms for the salt products for some applications due to the
difficulty in applying a uniform amount of these types of
materials.
An example preparation scheme is shown in Scheme 1:
##STR00015##
Here, R can be the same as the other fatty acid groups or a
different fatty acid group. Exemplary amines and other organic
bases which can be used in the neutralization are described above.
As will be appreciated, in the case of an inorganic base, the
neutralization can be carried out by reacting the mixture of
anhydride-capped mono- and diglycerides with an aqueous solution of
ammonia or a metal hydroxide, such as sodium or calcium
hydroxide.
Corrosion Inhibiting Composition
An organic salt of a glyceride-cyclic carboxylic acid anhydride
adduct as described above can be utilized as a corrosion inhibitor
in a corrosion inhibiting composition. The corrosion inhibiting
composition may include from 0.01-30 wt. % of the mixture of
organic salts of half ester-half acids according to STRUCTURE (1)
or (2). In various embodiments, the corrosion inhibiting
composition includes at least 0.25 wt. % or at least 1 wt. % of the
mixture of organic salts according to STRUCTURE (1) or (2), and in
some embodiments, up to 25 wt. %, or up to 10 wt. %, or up to 5 wt.
%.
The composition further includes at least one diluent in which the
exemplary mixture of salts is substantially dispersed or dissolved.
The diluent is a generally a liquid with a viscosity of less than
500 mPas or less than 150 mPas, at ambient temperature (25.degree.
C.). The diluent may be selected from organic solvents, petroleum
and vegetable oils, water, and combinations thereof. The diluent
may be present in the corrosion inhibiting composition at a total
concentration of at least 10 wt. %, such as at least 20 wt. %, or
at least 50 wt. %, or at least 70 wt. % and in one embodiment, up
to 99.99 wt. %, or up to 99.75 wt. %, or up to 99 wt. % diluent. In
some embodiments, the corrosion inhibiting composition is in the
form of an oil-in-water or water-in-oil emulsion.
The composition may further include one or more adjuvants selected
from natural and synthetic waxes, fatty acids, normal and overbased
detergents, such as metal sulfonates, other corrosion inhibitors,
surfactants, demulsifiers, defoamers, biocidal agents, viscosity
modifiers, pigments, and the like.
Example Diluents
Example liquid diluents suitable for use in the corrosion
inhibiting composition include water, volatile organic solvents,
and oils of lubricating viscosity. In general, the diluent may
serve as a carrier solvent and/or as the continuous phase of an
emulsion.
Exemplary volatile organic solvents include alcohols, glycols,
toluene, aromatic solvents, terpenoids, terpenes, esters, ethers,
acetals, polar aprotic solvents, ketones, and derivatives and
combinations thereof. Examples include aromatics, such as xylene,
toluene, benzene, and halogenated derivatives, such as
chlorobenzene; esters such as ethyl acetate, n-butyl acetate,
isobutyl acetate, methylglycol acetate, ethylglycol acetate,
methoxypropyl acetate, 2,2,4-trimethyl-1,3-pentanediol
monoisobutyrate, dipropylene glycol monomethyl ether acetate,
propylene glycol monoethyl ether acetate, propylene glycol
monomethyl ether acetate, ethylene carbonate, methyl acetate, ethyl
lactate, methyl formate; ethers such as butyl glycol,
tetrahydrofuran, dioxane, ethylglycol ether, diethylene glycol
monoethyl ether, diethylene glycol monomethyl ether, diethylene
glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether,
diethylene glycol diethyl ether, diethylene glycol dimethyl ether,
diethylene glycol di-n-butyl ether, diethylene glycol di-n-hexyl
ether, ethylene glycol bis-2-ethylhexyl ether, ethylene glycol
di-n-butyl ether, ethylene glycol di-n-hexyl ether, ethylene glycol
di-n-propyl ether, dipropylene glycol dimethyl ether, dipropylene
glycol monomethyl ether, dipropylene glycol mono-n-butyl ether,
dipropylene glycol mono-n-propyl ether, dipropylene glycol
mono-tert-butyl ether, dipropylene glycol di-tert-butyl ether,
propylene glycol monoethyl ether, propylene glycol monomethyl
ether, propylene glycol mono-n-propyl ether, propylene glycol
monophenyl ether, propylene glycol mono-tert-butyl ether, propylene
glycol diphenyl ether, propylene glycol mono-n-butyl ether,
tripropylene glycol monomethyl ether, and poly(allyl glycidyl
ether); ketones such methyl ethyl ketone; alcohols and glycols,
such as methanol, ethanol, isopropanol (IPA), propanol, butanol,
isobutanol, tert-butanol, ethylene glycol, diethylene glycol,
propylene glycol, 1,3-propanediol, butanediol, benzyl alcohol,
glycerine; polar aprotic solvents such as dimethylformamide, DMPU
(dimethyl pyrimidinone), DMSO (dimethyl sulfoxide),
dimethylacetamide, N-methylpyrrolidone, dimethyl acetamide,
tetrahydrofuran, acetonitrile, acetone; acetals, such as
dimethoxymethane, dibutoxymethane, glycerol formal,
diethoxymethane; halogenated solvents, such as methylene chloride
and trichloromonofluoroethane; dibutyl phthalate, tris(butoxyethyl)
phosphate, low-boiling naptha (liquid hydrocarbon mixtures with a
boiling point between 30.degree. C. and 90.degree. C.), and mineral
spirits (a mixture of predominantly aliphatic and alicyclic C6 to
C12 hydrocarbons, with a maximum content of 25% of C7 to C12
aromatic hydrocarbons and a boiling point typically between
60.degree. C. and 70.degree. C.).
In general, the volatile organic solvent can be any compound that
is formed from the elements carbon and hydrogen, with optionally
one or more of oxygen, nitrogen, halogen and phosphorus (excluding
the exemplary salt mixture, carbon monoxide, carbon dioxide,
carbonic acid, and ammonium carbonate). The volatile organic
solvent is generally a compound in which the salt is soluble, when
present in at least the lowest concentrations disclosed herein. The
volatile organic solvent can have a boiling point of up to
250.degree. C. when measured at a standard atmospheric pressure of
101.3 kPa.
The volatile organic solvent(s) may be present in the
corrosion-inhibiting composition at from 0.1 to 99.9 wt. %, e.g.,
50 to 99.9 wt. %, or 90 to 99.5 wt. % or 95 to 99.5 wt. %.
Oils useful herein include naphthenic and paraffinic mineral oils,
which may be refined or unrefined. Unrefined oils are those
obtained directly from a natural or synthetic source without
further purification. For example, a shale oil obtained directly
from retorting operations, a petroleum oil obtained directly from
distillation or ester oil obtained directly from an esterification
process and used without further treatment would be an unrefined
oil. Refined oils are similar to the unrefined oils except that
they have been further treated in one or more purification steps to
improve one or more properties. Purification techniques include
solvent extraction, acid or base extraction, filtration,
percolation, or similar purification techniques. Exemplary
synthetic lubricating oils include hydrocarbon oils such as
polymerized and interpolymerized olefins (e.g., polybutylenes,
polypropylenes, propylene-isobutylene copolymers, poly(1-hexenes,
poly(1-octenes), poly(1-decenes), and mixtures thereof);
alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes,
dinonylbenzenes, and di(2-ethylhexyl)-benzenes); polyphenyls (e.g.,
biphenyls, terphenyls, and alkylated polyphenyls), alkylated
diphenyl ethers and alkylated diphenyl sulfides and the
derivatives, analogs, and homologs thereof.
Other suitable oils are natural oils such as animal oils and plant
oils, such as castor oil, cottonseed oil, rapeseed oil, soybean
oil, and lard oil.
The diluent may be present at a total concentration of 0.1-99.9 wt.
% of the corrosion-inhibiting composition. In one embodiment, the
lubricating oil is present at up to 60 wt. % of the
corrosion-inhibiting composition, e.g., at least 5 wt. %.
The examples below suggest that for good protection against
corrosion, suitable carrier solvents are generally those that
evaporate completely within a short time, such as solvents with a
boiling point of below 150.degree. C.
Example Adjuvants
Exemplary adjuvants which may be present in the
corrosion-inhibiting composition include natural and synthetic
waxes, fatty acids, normal and overbased detergents, such as metal
sulfonates, demulsifiers, other corrosion-inhibiting compounds,
biocidal agents, surfactants, and the like.
Example waxes include petroleum, synthetic, and natural waxes,
oxidized waxes, microcrystalline waxes, wool grease (lanolin) and
other waxy esters, and mixtures thereof. Petroleum waxes are
paraffinic compounds isolated from crude oil via some refining
process, such as slack wax and paraffin wax. Synthetic waxes are
waxes derived from petrochemicals, such as ethylene or propylene.
Synthetic waxes include polyethylene, polypropylene, and
ethylene-propylene co-polymers. Natural waxes are waxes produced by
plants and/or animals or insects. These waxes include beeswax, soy
wax and carnauba wax. Insect and animal waxes include beeswax,
spermaceti and the like. Petrolatum and oxidized petrolatum may
also be used in these compositions. Petrolatums and oxidized
petrolatums may be defined, respectively, as purified mixtures of
semisolid hydrocarbons derived from petroleum and their oxidation
products. Microcrystalline waxes may be defined as higher melting
point waxes purified from petrolatums.
The wax(es) may be present in the corrosion-inhibiting composition
at from 0.1 to 75 wt. %, e.g., 0.1 to 50 wt. %.
Fatty acids useful herein include monocarboxylic acids of about 8
to about 35 carbon atoms, and in one embodiment about 16 to about
24 carbon atoms. Examples of such monocarboxylic acids include
unsaturated fatty acids, such as myristoleic acid, palmitoleic
acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid,
linoleic acid, linoelaidic acid; .alpha.-linolenic acid;
arachidonic acid; eicosapentaenoic acid; erucic acid,
docosahexaenoic acid; and saturated fatty acids, such as caprylic
acid; capric acid; lauric acid, myristic acid; palmitic acid;
stearic acid, arachidic acid, behenic acid; lignoceric acid,
cerotic acid, isostearic acid, gadoleic acid, tall oil fatty acids,
combinations thereof, and the like. These acids may be saturated,
unsaturated, or have other functional groups, such as hydroxy
groups, as in 12-hydroxy stearic acid, from the hydrocarbyl
backbone. Other example carboxylic acids are described in U.S. Pat.
No. 7,435,707.
The fatty acid(s) may be present in the corrosion-inhibiting
composition at from 0.1-50 wt. %, e.g., 0.1 to 25 wt. %, or 0.1 to
10 wt. %.
Example overbased detergents include overbased metal sulfonates,
overbased metal phenates, overbased metal salicylates, overbased
metal saliginates, overbased metal carboxylates, overbased calcium
sulfonate detergents and the like. The overbased detergents contain
metals such as Mg, Ba, Sr, Zn, Na, Ca, K, and mixtures thereof and
the like. Overbased detergents are metal salts or complexes
characterized by a metal content in excess of that which would be
present according to the stoichiometry of the metal and the
particular acidic organic compound reacted with the metal, e.g., a
sulfonic acid.
The term "metal ratio" is used herein to designate the ratio of the
total chemical equivalents of the metal in the overbased material
(e.g., a metal sulfonate or carboxylate) to the chemical
equivalents of the metal in the product which would be expected to
result in the reaction between the organic material to be overbased
(e.g., sulfonic or carboxylic acid) and the metal-containing
reactant used to form the detergent (e.g., calcium hydroxide,
barium oxide, etc.) according to the chemical reactivity and
stoichiometry of the two reactants. Thus, while in a normal calcium
sulfonate, the metal ratio is one, in the overbased sulfonate, the
metal ratio is 4.5.
Examples of such detergents are described, for example, in U.S.
Pat. Nos. 2,616,904; 2,695,910; 2,767,164; 2,767,209; 2,798,852;
2,959,551; 3,147,232; 3,274,135; 4,729,791; 5,484,542 and
8,022,021.
The overbased detergents may be used alone or in combination. The
overbased detergents may be present in the range from about 0.1 wt.
% to about 20%; such as at least 1 wt. % or up to 10 wt. % of the
composition.
Exemplary surfactants include nonionic polyoxyethylene surfactants
such as ethoxylated alkyl phenols and ethoxylated aliphatic
alcohols, polyethylene glycol esters of fatty, resin and tall oil
acids and polyoxyethylene estesr of fatty acids or anionic
surfactants such as linear alkyl benzene sulfonates, alkyl
sulfonates, alkyl ether phosphonates, ether sulfates,
sulfosuccinates, and ether carboxylates.
Demulsifiers useful herein include polyethylene glycol,
polyethylene oxides, polypropylene alcohol oxides (ethylene
oxide-propylene oxide) polymers, polyoxyalkylene alcohol, alkyl
amines, amino alcohol, diamines or polyamines reacted sequentially
with ethylene oxide or substituted ethylene oxide mixtures,
trialkyl phosphates, and combinations thereof, and the like.
The demulsifier(s) may be present in the corrosion-inhibiting
composition at from 0.0001 to 10 wt. %, e.g., 0.0001 to 2.5 wt.
%.
Other corrosion inhibitors in addition to the exemplary compounds
may also be used in the compositions provided herein. The corrosion
inhibitors which may be used include thiazoles, triazoles and
thiadiazoles. Examples include benzotriazole, tolyltriazole,
octyltriazole, decyltriazole, dodecyltriazole,
2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole,
2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazoles,
2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazoles,
2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles, and
2,5-bis-(hydrocarbyldithio)-1,3,4-thiadiazoles. Other suitable
inhibitors of corrosion include ether amines; polyethoxylated
compounds such as ethoxylated amines, ethoxylated phenols, and
ethoxylated alcohols; imidazolines; and the like. Other suitable
corrosion inhibitors include alkenylsuccinic acids in which the
alkenyl group contains about 10 or more carbon atoms such as, for
example, tetrapropenylsuccinic acid, tetradecenylsuccinic acid,
hexadecenylsuccinic acid, and the like; long-chain alpha,
omega-dicarboxylic acids in the molecular weight range of about 600
to about 3000; and other similar materials. Other non-limiting
examples of such inhibitors may be found in U.S. Pat. Nos.
3,873,465, 3,932,303, 4,066,398, 4,402,907, 4,971,724, 5,055,230,
5,275,744, 5,531,934, 5,611,991, 5,616,544, 5,744,069, 5,750,070,
5,779,938, and 5,785,896; Corrosion Inhibitors, C. C. Nathan, ed.,
NACE, 1973; I. L. Rozenfeld, Corrosion Inhibitors, McGraw-Hill,
1981; Metals Handbook, 9.sup.th Ed., Vol. 13--Corrosion, pp.
478497; Corrosion Inhibitors for Corrosion Control, B. G. Clubley,
ed., The Royal Society of Chemistry, 1990; Corrosion Inhibitors,
European Federation of Corrosion Publications Number 11, The
Institute of Materials, 1994; Corrosion, Vol. 2--Corrosion Control,
L. L. Sheir, R. A. Jarman, and G. T. Burstein, eds.,
Butterworth-Heinemann, 1994, pp. 17:10-17:39; Y. I. Kuznetsov,
Organic Inhibitors of Corrosion of Metals, Plenum, 1996; and in V.
S. Sastri, Corrosion Inhibitors: Principles and Applications,
Wiley, 1998.
The other corrosion inhibitor(s) may be present in the
corrosion-inhibiting composition at from 0.0001 to 5 wt. %, e.g.,
0.0001 to 3 wt. %.
Exemplary biocidal agents include dehydroacetic acid,
3-isothiazolones, sodium pyridine-2-thiol-1-oxide,
3-iodo-2-propynyl-N-n-butyl carbamate, N,N-methylenebismorpholine,
(ethylenedioxy)dimethanol, 3,3-methylenebis(5-methyloxazolidine),
and the like.
Dispersants which may be included in the composition include those
with an oil soluble polymeric hydrocarbon backbone and having
functional groups that are capable of associating with particles to
be dispersed. The polymeric hydrocarbon backbone may have a weight
average molecular weight ranging from about 750 to about 1500
Daltons. Exemplary functional groups include amines, alcohols,
amides, and ester polar moieties which are attached to the polymer
backbone, often via a bridging group. Example dispersants include
Mannich dispersants, described in U.S. Pat. Nos. 3,697,574 and
3,736,357; ashless succinimide dispersants described in U.S. Pat.
Nos. 4,234,435 and 4,636,322; amine dispersants described in U.S.
Pat. Nos. 3,219,666, 3,565,804, and 5,633,326; Koch dispersants,
described in U.S. Pat. Nos. 5,936,041, 5,643,859, and 5,627,259,
and polyalkylene succinimide dispersants, described in U.S. Pat.
Nos. 5,851,965, 5,853,434, and 5,792,729.
The dispersant(s) may be present in the corrosion-inhibiting
composition at from 0.0001 to 50 wt. %, e.g., 1 to 25 wt. %.
The compositions disclosed herein may be used for a variety of
applications, such as storage and shipping coatings, slushing oils,
pickling oils, dip-tank fluids, penetrating oils, maintenance
coatings, architectural, industrial, and marine coatings, and the
like. In the case of longer-term coatings, such as pigmented and
non-pigmented paints, primers for paint, clear coat and base coat
paints, varnishes, lacquer and the like, the composition can
include additives suitable for such compositions, such as one or
more binders or resins, pigments, and combinations thereof.
Method of Forming the Corrosion-Inhibiting Composition
In one embodiment the composition is formed by dissolving a
hydrophobic salt mixture according to STRUCTURE (1) or (2) in a
volatile organic solvent at about 0.25-25 wt. % of the resulting
composition, such as at least about 1 wt. %, and in one embodiment,
up to 10 wt. % of the composition. Optionally, one or more
adjuvants are incorporated into the composition. Exemplary organic
solvents useful in this embodiment include aliphatic and aromatic
hydrocarbons; glycols such as glycerine, propylene glycol,
1,3-propanediol, and ethylene glycol; alcohols such as primary
alcohols (e.g., methanol, ethanol, propanol, the like, and
combinations thereof), secondary alcohols (e.g., isopropanol,
isobutanol, secondary butanol, the like, and combinations thereof),
and tertiary alcohols (e.g., t-butanol, the like, and combinations
thereof).
In some embodiments, the compounds according to STRUCTURE (1) or
(2) are sparingly or fully water-soluble. Corrosion-inhibiting
compositions may be suitably formulated in water or a mixture of
water and one or more organic solvents, such as one or more
alcohols and/or glycols.
In another embodiment the composition is formed by dissolving a
hydrophobic salt mixture according to STRUCTURE (1) or (2) in a
non-volatile petroleum oil, such as a paraffinic or naphthenic oil,
or vegetable oil at about 0.25-25 wt. % of the resulting
composition, such as at least about 1 wt. %, and in one embodiment,
up to 10 wt. %, into the composition. Optionally, one or more
adjuvants are incorporated into the composition.
As an example, the composition is formulated in a liquid
hydrocarbon mixture having a boiling point in the range of about
30.degree. C.-200.degree. C., such as an aromatic naptha, e.g.,
heavy aromatic naptha (boiling point in the range of 90.degree.
C.-200.degree. C.), to which one or more cosolvents, such as an
alcohol or glycol may be incorporated.
In another embodiment the composition is formed by dissolving an
emulsifiable salt mixture according to STRUCTURE (1) or (2) (for
example, a salt formed by neutralizing a glyceride-cyclic
carboxylic acid anhydride adduct with a water-soluble amine, such
as triethanolamine, an alkanolamine, or an inorganic hydroxide such
as NaOH) in water, at about 0.25-25 wt. % of the resulting
composition, such as at least about 1 wt. %, and in one embodiment,
up to 10 wt. % and an emulsion formed.
To form an emulsion, the salt mixture, solvent, water, and
optionally additional adjuvants are mixed under appropriate mixing
conditions to form the desired emulsion composition. The mixing may
include high shear mixing, low shear mixing, or a combination
thereof. The mixing may be conducted using a single mixing step or
in the alternative multiple mixing steps. The mixing may be
conducted on a batch basis, a continuous basis, or a combination
thereof. The mixing may be conducted at a temperature in the range
of about 0.degree. C. to about 100.degree. C., and in one
embodiment about 10.degree. C. to about 50.degree. C., for about 1
minute to about 30 hours.
Mode of Application
The composition may be applied directly to a bare metal surface,
for example, by painting, spraying, rolling, dip coating, or the
like to provide a layer of about 1 .mu.m to 1 mm in thickness. The
layer may provide a self-healing effect when the layer is
scratched, through evaporation and redeposition, or other
mechanism.
In other embodiments the corrosion-inhibiting composition may be in
the form of a paint which in addition to the compound according to
STRUCTURE (1) or (2) may further include one or more of pigments or
dyes, resins (alkyds, epoxies, etc.), and other components
conventionally used to provide a coating which serves as a more
permanent barrier to atmospheric and/or aqueous corrosion.
The metallic surfaces to be treated can be formed in whole or in
part from ferrous and/or non-ferrous metals. In general, the total
metal content of the body or surface of the body to be treated is
at least 10 wt. % or at least 30 wt. % or at least 50 wt. %, and
can be up to 99 or 100 wt. %. The metal body/surface may be a metal
or metal alloy, such as iron, steel, aluminum, copper, brass, or
the like where the total metal content may be at least 50 wt. % or
at least 70 wt. % of the entire body or of a metallic surface layer
to be protected. Suitable surfaces to be protected are those
subject to atmospheric pollution, such as building materials,
automobile parts, and the like, surfaces exposed to aqueous
environment's such as boilers, ship components, submerged
platforms, and the like, and surfaces exposed to oils and fuels,
such as engines, gas and oil pipelines, and the like.
The metal part to be protected can be dipped into, sprayed with,
brushed with, or otherwise coated with the resulting
solution/emulsion. In the case of a composition containing a
volatile solvent, the volatile organic solvent can then be
evaporated from the composition film. After the volatile organic
solvent has evaporated, a thin, rust preventive film of the
hydrophobic salt adheres to the metal part.
In the case of compositions containing non-volatile diluents, the
metal part to be protected may be dipped into, sprayed with, or
otherwise coated with the solution. A thin, rust preventive film of
the hydrophobic salt in combination with the non-volatile oil
remains coated on the metal part.
In the case of compositions in the form of emulsions, the metal
part to be protected may be dipped into, sprayed with, or otherwise
coated with the emulsion. After the water has evaporated, a thin,
rust preventive film of the emulsifiable salt adheres to the metal
part.
In each case, a conventional paint may be subsequently applied. In
another embodiment, the salt-containing film may be removed prior
to further processing of the metal part. In another embodiment, the
composition is in the form of a paint or other coating.
The examples below suggest that the salts disclosed herein are
efficacious corrosion inhibitor compounds that can significantly
delay the onset of atmospherically-induced rust on bare ferrous
metal articles, such as freshly cast, milled, or worked iron or
steel pieces or parts, by way of example.
EXAMPLES
The following methods can be used for preparation of organic salts
of glyceride-cyclic carboxylic acid anhydride adducts.
The following reactants were employed:
Vegetable-Derived Triglycerides:
As example triglycerides, soybean oil (SYBO), rapeseed oil (RPSO),
coconut oil (ONTO) (obtained from Cargill Industrial Oils and
Lubricants), tallow oil (obtained from Werner G. Smith Co,
Cleveland Ohio), and two partially hydrogenated derivatives of
soybean oil available commercially from Cargill Industrial Oils and
Lubricants under the trade names S-113 Wax and S-130 Wax (S-113 and
S-130) were obtained. S-113 is a partially hydrogenated soybean oil
stock wax with melting point .about.113.degree. F.
(.about.45.degree. C.); S-130 is a partially hydrogenated soybean
oil stock wax with melting point .about.130.degree. F.
(.about.54.degree. C.).
These triglycerides serve to illustrate the effects of varying the
degree of carbon-carbon unsaturation in the triglyceride as well as
the effect of the melting point of the triglyceride.
Cyclic Carboxylic Acid Anhydrides:
The following cyclic carboxylic acid anhydrides were evaluated:
SA=succinic anhydride (dihydro-2,5-furanedione), CAS#108-30-5,
obtained from Aldrich Chemical Company.)
HHPA=hexahydrophthalic anhydride
(hexahydro-1,3-isobenzofurandione), CAS#85-42-7, obtained from
Dixie Chemical Company.
MHHPA=methylhexahydrophthalic anhydride
(hexahydromethyl-1,3-isobenzofurandione), CAS#25550-51-0, obtained
from Dixie Chemical Company.
OSA=octenylsuccinic anhydride
(dihydro-3-(octen-1-yl)-2,5-furandione), CAS#26680-54-6, obtained
from Dixie Chemical Company.
ODSA=octadecenyl succinic anhydride, CAS#68784-12-3, obtained from
Dixie Chemical Company.
Structures of these cyclic carboxylic anhydrides are as shown
below:
##STR00016## Transesterification Catalysts
As a transesterficiation catalyst, butyltin tris(2-ethylhexanoate)
(BTEH), was used, which is available as Fascat.RTM. 4102 from PMC
Organometallix.
Organic Bases:
The following organic bases were evaluated:
2-(2-aminoethoxy)ethanol; 5-amino-1-pentanol; 3-amino-1-propanol;
2-(2-aminoethoxy)ethanol (AEE); N,N-diethylethanolamine (DEEA);
3-dimethylamino-1-propylamine (DMAPA); N,N-dimethylethanolamine
(DMEA); 2-ethylhexylamine (EHAM); imidazole;
isododecyloxypropylamine, CAS#68511-40-0, obtained from Air
Products Inc. under the trade name PA-16; 3-methoxypropylamine;
1-methylimidazole; 2-methylimidazole; tributylamine;
triethanolamine; triisopropanolamine and Primene.RTM. 81-R--a
mixture of C.sub.10-C.sub.15 tert-alkyl primary amines
(CAS#68955-53-3), now available from Dow Chemical Co.
A. Example Preparation of Glyceride Mixtures (Step 1)
Examples 1 through 8 demonstrate the preparation of several
glyceride mixtures from a variety of starting triglyceride oils
using different molar ratios of triglyceride oil to glycerin in the
reaction mixture.
Example 1
Soybean Oil+Glycerin 2:1 (SYBO-GLY 2:1)
Soybean Oil (1424 grams, 1.63 moles) and glycerin (75 grams, 0.814
moles) were combined in a 2-liter, 3-neck round-bottom flask
equipped with a mechanical stirrer, nitrogen inlet, nitrogen outlet
through a soybean oil-filled bubbler, and a heating mantle
connected to a digital temperature controller. This equipment
configuration is used in many of the following examples with
different sized flasks. The 2-phase mixture was heated to
180.degree. C. with agitation. BTEH (1.55 grams, 0.0026 mole) was
then added to catalyze the transesterification reaction. The
mixture was held at 180.degree. C. for 8 hours with a continuous
slow nitrogen sweep through the vapor space of the flask. The
resultant soybean oil glyceride mixture was recovered in
essentially quantitative yield as hazy yellow oil. The calculated
average molecular weight of this material is 613.95 g/mole.
Example 2
Soybean Oil+Glycerin 1:1 (SYBO-GLY 1:1)
Using the same reaction apparatus as in Example 1, soybean oil
(1355 grams, 1.55 mole) and glycerin (142.5 grams, 1.55 moles) were
heated to 180.degree. C. and then BTEH (2.3 grams, 0.0038 mole) was
added as a catalyst. The mixture was heated at 180.degree. C. for
11 hours under nitrogen. The product glyceride, containing an
average of 1.5 fatty acid residues per molecule, was recovered in
quantitative yield. Upon cooling, the product was a yellow oil that
partially froze. The calculated average molecular weight of this
material is 483.5 g/mole; the calculated average m.w. per OH group
is 322.33.
Example 3
Soybean Oil+Glycerin 1:2 (SYBO-GLY 1:2)
Using the same reaction apparatus as in Example 1, soybean oil
(1240 grams, 1.42 mole) and glycerin (260 grams, 2.82 moles) were
heated to 180.degree. C. and then BTEH (1.91 grams, 0.0032 mole)
was added as a catalyst. The mixture was heated at 180.degree. C.
for 9 hours under nitrogen. The resultant product had two layers.
The IR spectra of the layers were essentially identical except for
the intensity of the broad OH peak at 3340 cm-1. The layers were
not separated. The combined amount of the two layers represented an
essentially quantitative yield. Both layers substantially froze
upon cooling. The product was thoroughly re-mixed before using it
to prepare subsequent derivatives. The calculated average molecular
weight of this material is 353.0 g/mole; the calculated average
m.w. per OH group is 176.5.
Example 4
Cargill S-113+Glycerin 2:1 (S113-GLY 2:1)
Using a 1-liter flask equipped as for Example 1, molten Cargill
S-113 Wax (663 grams, 0.75 mole) and glycerin (34.6 grams, 0.376
moles) were heated to 180.degree. C. and then BTEH (1.50 grams,
0.0025 mole) was added as a catalyst. The mixture was heated at
180.degree. C. for a total of eight hours under nitrogen. The
product glyceride mixture was recovered quantitatively. It froze to
a hard wax at room temperature. The estimated average molecular
weight of this material is 619.2 g/mole.
Example 5
Cargill S-130+Glycerin 2:1 (S130-GLY 2:1)
Using a 1-liter flask equipped as for Example 1, molten Cargill
S-130 Wax (663 grams, 0.75 mole) and glycerin (34.5 grams, 0.375
moles) were heated to 180.degree. C. and then BTEH (1.45 grams,
0.0024 mole) catalyst was added. The mixture was heated at
180.degree. C. for 8 hours under nitrogen. The product glyceride
mixture was recovered quantitatively. It froze into a hard wax at
room temperature. The estimated average molecular weight of this
material is 621.6 g/mole.
Example 6
Tallow Oil+Glycerin 2:1 (TALLOW-GLY 2:1)
Using a 1-liter flask equipped as for Example 1, molten tallow oil
(521 grams, 0.61 mole) and glycerin (28.0 grams, 0.304 mole) were
heated to 180.degree. C. and then BTEH (0.62 grams, 0.0010 mole)
catalyst was added. The mixture was heated at 180.degree. C. for 9
hours under nitrogen. The product glyceride mixture had an
unpleasant odor compared to chemically-similar vegetable-based
glycerides. It froze into a wax at room temperature.
Example 7
Coconut Oil+Glycerin 2:1 (ONTO-GLY 2:1)
Using a 1-liter flask equipped as for Example 1, molten Cargill
Ultimate 76 Coconut Oil having a saponification number of 250.6 mg
KOH/g (652 grams, 0.971 mole) and glycerin (45.0 grams, 0.489 mole)
were heated to 180.degree. C. and then BTEH (1.37 grams, 0.0023
mole) catalyst was added. The mixture was heated at 180.degree. C.
for 8 hours under nitrogen. The product glyceride mixture was hazy
while molten and froze into a wax at room temperature. The
calculated average molecular weight of this material is 477.6
g/mole.
Example 8
Rapeseed Oil+Glycerin 1.5:1 (RPSO-GLY 1.5:1)
Using a 2-liter flask equipped as in Example 1, rapeseed oil (1400
grams, 1.56 mole) and glycerin (96.0 grams, 1.04 mole) were heated
to 180.degree. C. and then BTEH (2.81 grams, 0.0046 mole) catalyst
was added. The mixture was heated at 180.degree. C. for 8 hours
under nitrogen. The product glyceride mixture was hazy yellow oil
having an acid number of 0.22 mg KOH/g. The product partially froze
upon standing. The estimated average molecular weight per glyceride
is 575.0 g/mole.
B. Example Cyclic Carboxylic Acid Anhydride Adducts of Glyceride
Mixtures (Step 2)
Examples 9 through 26 demonstrate how the glyceride mixtures of
Examples 1-8 can be further reacted with cyclic carboxylic acid
anhydrides to form glyceride half-acid/half-ester adducts.
Example 9
Soybean Oil+Glycerin (2:1)+Succinic Anhydride 1:1 (SYBO-GLY-SA
2:1:3)
A glyceride mixture was prepared using soybean oil (244 grams,
0.279 mole), glycerin (13.03 grams, 0.141 moles), and BTEH (0.70
grams, 0.0012 mole), which were heated to 180.degree. C. in a
500-mL flask equipped as in Example 1. The mixture was held at
180.degree. C. for 6 hours under nitrogen.
After standing overnight at room temperature, the glyceride mixture
was reheated to 130.degree. C. and succinic anhydride (42.10 g,
0.420 mole) was added in a single portion, dropping the temperature
to about 116.degree. C. The temperature was re-established at
130.degree. C. and the reaction mixture was held at this
temperature until the succinic anhydride had all dissolved,
resulting in a clear liquid. Fine crystals of succinic anhydride
formed in the vapor space of the flask and these had to be manually
knocked back down into the reaction mixture. Samples were withdrawn
periodically and titrated for acid number. The acid number dropped
for about five hours, and then stalled at a value of about 77-78 mg
KOH/g, indicating an essentially complete reaction. The product, a
soy diglyceride-succinate half-acid ester, was a clear yellow
oil.
Example 10
Soybean Oil+Glycerin (2:1)+Hexahydrophthalic Anhydride 1:1
(SYBO-GLY-HHPA 2:1:3)
The glyceride mixture from Example 1 (326 g, 0.531 mole) and molten
HHPA (74.0 g, 0.480 mole) were weighed directly into a tared
500-mL, 3-neck round-bottom flask. The flask was equipped as in
Example 1. The mixture was heated to 120.degree. C. and the
progress of the reaction was tracked by periodic sampling for the
acid number of the mixture. After 7 hours, the acid number had
declined from an initial (calculated) value of 134.7 to 74.0 mg
KOH/g, indicating about 90% reaction of the HHPA. The batch was
cooled at this point, giving an essentially complete recovery of
the soy diglyceride-hexahydrophthalate half-acid ester as a clear
yellow oil.
Example 11
Soybean Oil+Glycerin (2:1)+Methylhexahydrophthalic Anhydride 1:1
(SYBO-GLY-MHHPA 2:1:3)
The glyceride product from Example 1 (320.0 g, 0.521 mole) and
MHHPA (80.0 g, 0.476 mole) were combined in a 500-mL flask equipped
as for Example 1. The mixture was heated to 130.degree. C. for a
period of 6 hours. The product was titrated twice for the acid
number, with results of 73.8 and 72.4 mg KOH/g, indicating about
89-92% reaction of the MHHPA. The resulting soy
diglyceride-methylhexahydrophthalate half-acid ester was a clear
yellow oil.
Example 12
Soybean Oil+Glycerin (1:1)+Methylhexahydrophthalic Anhydride 1:1
(SYBO-GLY-MHHPA 1:1:2)
The soy glyceride mixture from Example 2, average m.w. of 483.49
(297 g, 0.614 mole) and MHHPA (103 g, 0.613 mole) were reacted
together at 120.degree. C. for a period of 5.5 hours in the same
apparatus as for Example 11. The acid number stalled at 92.1 mg
KOH/g, which indicates about 93% reaction of the MHHPA. The product
was a viscous, clear yellow oil.
Example 13
Soybean Oil+Glycerin (1:2)+Octadecenylsuccinic Anhydride 1:1
(SYBO-GLY-ODSA 1:2:3)
The glyceride mixture of Example 3 was thoroughly re-mixed prior to
weighing in order to ensure a uniform sample. The glyceride mixture
(50.0 g, 0.142 mole) and ODSA (50.0 g, 0.140 mole) were combined in
a glass jar and mixed by shaking. The jar was placed in an
80.degree. C. oven for three days; an IR spectrum taken after the
3-day low-temperature cook still showed significant unreacted
anhydride and the mixture was composed of two layers. The mixture
was then heated on a hot plate with magnetic stirring at
130-135.degree. C. for about 5 hours. The acid number after this
second cooking was 79.8 mg KOH/g, indicating over 98% reaction of
the ODSA. The product was a hazy, viscous, golden-orange liquid.
The IR spectrum of the final product showed almost no
anhydride.
Example 14
Cargill S-113+Glycerin (2:1)+Succinic Anhydride 1:1 (S113-GLY-SA
2:1:3)
The molten glyceride from Example 4 (201 g, 0.325 mole) and
succinic anhydride (29.0 g, 0.290 mole) were combined in a 250-mL
flask that was equipped as in Example 1. The slurry was heated to
120.degree. C. for about 3 hours, during which time the succinic
acid solids disappeared. The acid number dropped to 70.0 mg KOH/g,
indicating 100% reaction of the succinic anhydride. The diglyceride
succinate half-acid ester was a slightly hazy yellow oil when
molten that froze to a white wax below about 40.degree. C.
Example 15
Cargill S-113+Glycerin (2:1)+Hexahydrophthalic Anhydride 1:1
(S113-GLY-HHPA 2:1:3)
Molten glyceride from Example 4 (245 g, 0.369 mole) and molten HHPA
(55 g, 0.357 mole) were combined at .about.80.degree. C. in a
500-mL flask that was equipped as in Example 1. The mixture was
heated to 120.degree. C. for about 4 hours. The final acid number
was 71.6 mg KOH/g, indicating about 93% reaction of the HHPA. The
diglyceride hexahydrophthalate half-acid ester was a clear yellow
oil that froze to a soft white wax below about 40.degree. C.
Example 16
Cargill S-113+Glycerin (2:1)+Octenylsuccinic Anhydride
(S113-GLY-OSA 2:1:3)
Molten glyceride from Example 4 (229 g, 0.370 mole) and OSA (71.1
g, 0.335 mole) were combined at .about.45.degree. C. in a 500-mL
flask that was equipped as described in Example 1. The mixture was
heated to 120.degree. C. for about 3.5 hours. The final acid number
was 68.3 mg KOH/g, indicating about 91% reaction of the OSA. The
product was a clear yellow oil while molten. It froze into a
semi-solid paste upon cooling.
Example 17
Cargill S130+Glycerine (2:1)+Methylhexahydrophthalic Anhydride
(S130-GLY-MHHPA 2:1:3)
The glyceride mixture from Example 5 (241 g, 0.387 mole) was melted
and heated to 106.degree. C. in a 500-mL flask equipped as for
Example 1. MHHPA (59.4 g, 0.353 mole) was added in a single portion
and the batch was allowed to cool to 45.degree. C. with the heat
turned off. The batch was then heated to 120.degree. C. About 5
hours after the MHHPA was added, the acid number was 69.6 mg KOH/g,
which indicates about 94% reaction of the anhydride. The product
glyceride-half ester/half acid adduct was recovered quantitatively.
The freezing range of the product was about 36-37.degree. C. The
frozen product was a very soft, off-white wax.
Example 18
Soybean Oil+Glycerin+Hexahydrophthalic Anhydride (SYBO-GLY-HHPA
2:1:3)
Soybean oil (1894 g, 2.165 mole) and glycerin (100.0 g, 1.086 mole)
were combined in a 3-liter flask equipped as for Example 1 and
heated to 180.degree. C. The temperature reached 180.degree. C.
about 45 minutes after heating commenced. Dibutyltin dilaurate
catalyst (7.00 g, 0.011 mole) was added to the mixture at about
160.degree. C. as it heated up. After about 1 hour at 180.degree.
C., there was no visible sign of a separate glycerin phase. Heating
at 180.degree. C. was continued for a total of six hours, after
which the reaction mixture was allowed to cool under nitrogen and
stand at room temperature for three days, during which time the
glyceride mixture partially froze. The batch was re-melted by
gentle warming and a 400-g portion was removed as a retained
sample.
The balance of the batch (1600 g, .about.2.606 mole assuming a
calculated m.w. of 614 g/mole) was heated to about 55.degree. C.
Meanwhile, hexahydrophthalic anhydride (HHPA) was melted in a
40.degree. C. oven. Molten HHPA (364.8 g, 2.366 mole) was added to
the diglyceride mixture in a single portion and the resulting
mixture heated to 130.degree. C. The batch was sampled
intermittently for an acid number analysis. About six hours after
the HHPA addition, the acid number had stopped dropping, stalling
at a value of 74.5 mg KOH/g, indicating 91.8% reaction of the HHPA.
An IR spectrum of the product showed very little remaining
anhydride functionality.
The product was a golden-yellow liquid having a Gardner color of
2.8. The viscosity was measured as 127.7 cSt at 40.degree. C. and
15.54 cSt at 100.degree. C. The density was measured as 0.9610
g/cm.sup.3 at 49.degree. C. and 0.9821 g/cm.sup.3 at 15.degree. C.
The pour point of the product was less than -13.degree. C.
Example 19
Coconut Oil+Glycerin (2:1)+Succinic Anhydride (CNTO-GLY-SA
2:1:3)
Molten coconut oil glyceride from Example 7 (168 g, 0.353 mole) and
succinic anhydride (32.0 g, 0.320 mole) were weighed directly into
a 250-mL flask. The flask was equipped as for Example 1. The
mixture was heated to 125.degree. C. over a period of about one
hour, during which time the succinic anhydride substantially
dissolved. The progress of the reaction was tracked by periodic
titration of the acid number and by disappearance of the anhydride
absorbance bands in the IR spectrum. After 4.5 hours at 125.degree.
C., the acid number had declined to 94.5 mg KOH/g, indicating 94.7%
reaction of the succinic anhydride. The anhydride bands in the IR
were almost completely gone as well. The reaction mixture was
cooled at this point, yielding 99.5% material recovery of slightly
hazy yellow oil. There was a small amount of gelatinous residue
that settled to the bottom of the flask.
Example 20
Coconut Oil+Glycerin (2:1)+Hexahydrophthalic Anhydride
(CNTO-GLY-HHPA 2:1:3)
Molten coconut oil glyceride from Example 7 (155 g, 0.326 mole) and
molten HHPA (32.0 g, 0.320 mole) were weighed directly into a
250-mL flask. The flask was equipped as for Example 1. The mixture
was heated to 130.degree. C. over a period of about 80 minutes,
during which time the reaction mixture turned from turbid to clear.
After 5 hours at 130.degree. C., the acid number had declined to
87.6 mg KOH/g, indicating 93% reaction of the anhydride. The
anhydride bands in the IR were very small at this point. The total
material recovery was 99.6%. The product was a crystal-clear,
yellow oil.
Example 21
Coconut Oil+Glycerin (2:1)+methylhexahydrophthalic Anhydride
(CNTO-GLY-MHHPA 2:1:3)
Molten product from Example 7 (152 g, 0.320 mole) and MHHPA (48.0
g, 0.285 mole) were added to a 250-mL flask equipped as for Example
1. The mixture was heated to 130.degree. C. over a period of about
80 minutes and held at that temperature for a period of 5.5 hours
before cooling. The product had a final acid number of 84.3 mg
KOH/g (calculated 95% reaction of MHHPA). The IR spectrum showed
very little residual anhydride. The product was a clear, yellow oil
at room temperature.
Example 22
Coconut Oil+Glycerin (2:1)+Octenylsuccinic Anhydride (CNTO-GLY-OSA
2:1:3)
Using the same procedure as above, molten Example 7 product (143 g,
0.299 mole) and octenylsuccinic anhydride (57.0 g, 0.269 mole) were
heated together at 130.degree. C. for about five hours. The
resulting slightly hazy, yellow oil had an acid number of 82.0 mg
KOH/g (91% reaction of the OSA). Total recovery of the product was
about 99.8%. The IR spectrum was as expected.
Example 23
Rapeseed Oil+Glycerin (1.5:1)+Succinic Anhydride (RPSO-GLY-SA
3:2:5)
Thoroughly mixed product from Example 8 (303 g, 0.527 mole) and
succinic anhydride (47.50 g, 0.475 mole) were combined in a 500-mL
flask equipped as for Example 1. The 2-phase mixture was warmed
from ambient temperature to 120.degree. C. and held at that
temperature for a total of 5 hours. The acid number was 78 mg
KOH/g, calculated as 97.5% reaction of the succinic anhydride. An
IR spectrum of the product confirmed that there was only a trace of
unreacted anhydride. The product was a hazy yellow oil with about
2% of a dark gold, dense gelatinous residue that settled to the
bottom upon standing. The yield of product was over 99%.
Example 24
Rapeseed Oil+Glycerin (1.5:1)+Hexahydrophthalic Anhydride
(RPSO-GLY-HHPA 3:2:5)
The Example 8 product was mixed until visually homogeneous. This
material (282 g, 0.490 mole) and molten HHPA (68.0 g, 0.441 mole)
were combined in a 500-mL flask set up as for Example 1. The
resulting liquid mixture was warmed to 130.degree. C. over a period
of about 30 minutes and then held at 130.degree. C. for about 5
hours, at which time the acid number had dropped to 74.4 mg KOH/g,
indicating 94.7% reaction of the HHPA. The IR spectrum of the
product showed no discernible peaks in the anhydride region. The
cooled product was a crystal clear, yellow oil that was recovered
in over 99% yield.
Example 25
Rapeseed Oil+Glycerin (1.5:1)+Methylhexahydrophthalic Anhydride
(RPSO-GLY-MHHPA 3:2:5)
Well-mixed product from Example 8 (277 g, 0.482 mole) and MHHPA
(73.0 g, 0.434 mole) were combined in a 500-mL flask which was
equipped as for Example 1. The mixture was heated to 130.degree. C.
over a period of about 1 hour during which time the mixture changed
from hazy to clear. The reaction was held at 130.degree. C. for a
period of 4.5 hours. At the end of this time, the acid number was
73.4 mg KOH/g, indicating 94.5% reaction of the MHHPA. An IR
spectrum confirmed that the anhydride had substantially reacted.
The product was recovered in nearly quantitative yield as a
crystal-clear yellow oil.
Example 26
Rapeseed Oil+Glycerin (1.5:1)+Octenylsuccinic Anhydride
(RPSO-GLY-OSA 3:2:5)
Using the same procedure as for Example 25, Example 8 product (263
g, 0.457 mole) was reacted with octenylsuccinic anhydride (87.0 g,
0.410 mole) to yield a clear yellow oil having an acid number of
69.4 mg KOH/g (94.4% reaction) after 4 hours at 130.degree. C. The
IR confirmed the absence of any significant unreacted anhydride.
The product was a crystal-clear yellow oil that was recovered
quantitatively.
C. Organic Salts of Glyceride-Cyclic Carboxylic Acid Anhydride
Adducts
Examples 27 through 43 demonstrate how the glyceride-cyclic
carboxylic acid anhydride adducts of Examples 9 through 26 can be
neutralized with various bases to form exemplary rust-preventive
salts.
Example 27
(SYBO-GLY-SA 2:1:3) Salts
Various salts of the soy diglyceride-succinate half-acid ester of
Example 9 were prepared by simple mixing of 20-gram portions of the
Example 9 product with the bases shown in TABLE 1 in the indicated
amounts. The physical appearance of each salt is also noted in the
table. Mild heating was applied during the mixing of samples H and
J in order to aid the dissolution of these solid bases.
TABLE-US-00001 TABLE 1 Example Salts of SYBO-GLY-SA Sam- ple Base
mw grams Appearance 27A 50% aqueous NaOH 40.00 2.20 Opaque slurry,
pale yellow 27B triethanolamine 149.19 4.11 Viscous opaque gel,
yellow 27C diethylethanolamine 117.19 3.22 Clear yellow oil 27D
2-ethylhexylamine 129.25 3.56 Clear yellow oil 27E
isododecyloxypropyl- 250.00 6.88 Clear yellow oil amine 27G
tributylamine 185.35 5.10 Clear yellow oil 27H imidazole 68.05 1.87
Clear yellow oil 27I 1-methylimidazole 82.07 2.26 Clear yellow oil
27J 2-methylimidazole 82.07 2.26 Clear yellow oil
These examples illustrate that most organic salts of the Example 9
product are uniform oils, whereas the sodium salt is not.
Example 28
(SYBO-GLY-HHPA 2:1:3) Salts
Various salts of the Example 10 product were prepared by simple
unheated mixing of 30-gram portions of that material with the bases
shown in TABLE 2 in the indicated amounts. The physical appearance
of each salt is noted in the table. The appearance of the calcium
salt (28J) is after dilution by 50 wt. with 100-second naphthenic
oil. These examples suggest that the inorganic salts and some of
the alkanolamine salts (28C, 28D, 28E) have physical forms which
may be less desirable for some applications than other organic
salts.
TABLE-US-00002 TABLE 2 Example Salts of SYBO-GLY-HHPA Sam- ple Base
mw grams Appearance Alkali Metal Salts 28A 45% aqueous KOH 56.11
4.94 2-phase, oil & translucent gel 28B 50% aqueous NaOH 40.00
3.17 2-phase, oil over opaque slurry Amine Salts 28C
triethanolamine 149.19 5.91 2 phase, oil over viscous turbid oil
28D monoethanolamine 61.08 2.42 Orange oil w. slight precipitate
28E 3-amino-1-propanol 75.11 2.97 Turbid, very viscous oil 28F
3-methoxypropylamine 89.14 3.53 Clear yellow oil 28G
diethylethanolamine 117.19 4.64 Clear orange oil 28H 2-(2-aminoeth-
105.14 4.16 Clear golden oil oxy)ethanol 28I 2-ethylhexylamine
129.25 5.12 Clear yellow oil Alkaline Earth Salt 28J Calcium oxide
56.08 1.11 Hard, turbid gel
Example 29
(SYBO-GLY-MHHPA 2:1:3) Salts
Several salts of Example 11 were produced by mixing 35-gram
portions of that material with the bases shown in TABLE 3 in the
indicated amounts. The physical appearance of each salt is noted in
the table. The appearance of the calcium salt (29J) is after
dilution by 50 wt. % with 100-second naphthenic oil.
TABLE-US-00003 TABLE 3 Example Salts of SYBO-GLY-MHHPA Sam- ple
Base mw grams Appearance Alkali Metal Salts 29A 45% aqueous KOH
56.11 5.63 2 Yellow oil phases 29B 50% aqueous NaOH 40 3.61 White
solids in yellow oil Amine Salts 29C triethanolamine 149.19 6.74
Turbid v viscous yellow oil 29D monoethanolamine 61.08 2.76 Clear v
viscous yellow oil 29E diethylethanolamine 117.19 5.29 Clear
viscous yellow oil 29F imidazole 68.05 3.07 Clear viscous yellow
oil 29G 1-methylimidazole 82.07 3.71 Clear yellow oil 29H
2-methylimidazole 82.07 3.71 Clear yellow oil 29I 2-ethylhexylamine
129.25 5.84 Clear yellow oil Alkaline Earth Salt 29J Calcium Oxide
56.08 1.27 Yellow gel with unreacted CaO
The physical forms exhibited by inorganic salts and some
alkanolamine salts (29C) may be undesirable for some
applications.
Example 30
(SYBO-GLY-MHHPA 2:1:3) Salts
Example 11 was repeated, yielding a glyceride half-ester/half-acid
having an acid number of 71.9 mg KOH/g. This batch was used to
produce additional amine salts by mixing 35 g portions of the
glyceride half-ester/half-acid with the amines shown in TABLE 4 in
the indicated amounts. The physical appearance of each salt is
noted in the table.
TABLE-US-00004 TABLE 4 Example Salts of SYBO-GLY-MHHPA Sam- ple
Base mw grams Appearance 30A 3-amino-1-propanol 75.11 3.37 Very
viscous yellow oil 30B 3-methoxypropylamine 89.14 4.00 Viscous
yellow oil 30C 2-(2-aminoeth- 105.14 4.72 Viscous yellow oil
oxy)ethanol 30D 5-amino-1-pentanol 103.17 4.63 Viscous yellow oil
30E dimethylethanolamine 89.14 4.00 Viscous yellow oil 30F
triisopropanolamine, 191.27 10.09 Turbid, v viscous 85% yellow
oil
Example 31
(SYBO-GLY-MHHPA 2:1:3) Salts
A large-scale preparation combining the steps of Examples 1 and 11
was accomplished by first reacting soybean oil (1518 g, 1.735 mole)
and glycerin (80.0 g, 0.869 mole) in the presence of BTEH (1.33
grams, 0.0022 mole) catalyst at 180.degree. C. for five hours. The
batch was then cooled to room temperature, and
methylhexahydrophthalic anhydride (400.8 g, 2.383 mole) was added.
The mixture was then heated to 130.degree. C. for seven hours,
during which time the acid number dropped to 70.0 mg KOH/g. An IR
spectrum of the product showed a negligible anhydride peak. At
total of 1993 g (exclusive of acid number samples) of soy glyceride
half ester/half acid was recovered as a clear golden-yellow oil.
This material was used to produce additional amine salts similar to
Examples 29 and 30 by mixing 35 g portions of the glyceride
half-ester/half-acid with the amines shown in TABLE 5 in the
indicated amounts.
TABLE-US-00005 TABLE 5 Example Salts of SYBO-GLY-MHHPA Sam- ple
Base mw grams Appearance 31A Ammonium 35.05 3.05 2-phase, yellow
oils hydroxide, 50% 31B Tetramethyl- 91.11 39.66 White emulsion
over ammonium clear yellow aqueous hydroxide, 10% in layer H.sub.2O
31C morpholine 87.12 3.79 Orange gel & yellow oil Tertiary
Amines 31D triethylamine 101.19 4.40 White gel & yellow oil 31E
Tributylamine 185.35 8.07 Yellow gel and reddish oil Secondary
Amines 31F dibutylamine 129.25 5.63 Clear orange oil 31G
bis(2-ethylhexyl)amine 241.46 10.51 Slightly hazy orange oil
Primary Amines 31H 1-octylamine 129.25 5.63 Clear yellow oil 31I
2-ethylhexylamine 129.25 5.63 Clear golden oil 31J Primene 81-R
189.89 8.28 Clear yellow oil
Examples 29, 30, and 31 show that for this soy-MHHPA glyceride half
ester/half acid, the simple inorganic salts (KOH, NaOH, CaO,
ammonia) are multi-phase mixtures. Similarly, most of the tertiary
amine salts (triethanolamine, triisopropanolamine, triethylamine,
tributylamine) gave turbid or semi-gelatinous salts. The secondary
amine salts (dibutylamine, bis(2-ethylhexylamine), and morpholine)
were higher in color than the primary amine salts.
Example 32
(SYBO-GLY-MHHPA 1:1:2) Salts
Several salts of the Example 12 product were prepared by simple
unheated mixing 30 g portions of that material with the bases shown
in TABLE 6 in the indicated amounts. The physical appearance of
each salt is also noted. The calcium salt (32J) was prepared by
diluting the Example 12 calcium oxide mixture to 50 wt. % with
100-second naphthenic oil and heating to .about.70.degree. C. with
vigorous mixing.
TABLE-US-00006 TABLE 6 Example Salts of SYBO-GLY-MHHPA Sam- ple
Base mw grams Appearance Alkali Metal Salts 32A 45% KOH 56.11 6.14
Yellow oil 32B 50% NaOH 40.00 3.94 Paste with solid precipitate
Amine Salts 32C Triethanolamine 149.19 7.35 Very viscous golden oil
32D Monoethanolamine 61.08 3.01 Viscous yellow oil 32E
3-amino-1-propanol 75.11 3.70 Viscous golden oil 32F
3-methoxypropylamine 89.14 4.39 Yellow oil 32G Diethylethanolamine
117.19 5.77 Golden oil 32H 2-(2-aminoeth- 105.14 5.18 Viscous
yellow oil oxy)ethanol 32I 2-ethylhexylamine 129.25 6.36 Yellow oil
Alkaline Earth Salts 32J Calcium oxide 56.08 1.38 Turbid, stiff,
yellow gel
It may be noted that the KOH salt is a uniform oil whereas the NaOH
salt is not.
Example 33
(SYBO-GLY-ODSA 1:2:3) Salts
Five salts of the Example 13 product were prepared by combining 20
g portions of Example 13 with bases in the amounts shown in TABLE
7.
TABLE-US-00007 TABLE 7 Example Salts of SYBO-GLY-ODSA Sam- ple Base
mw grams Appearance 33A diethylethanolamine 117.19 3.33 Viscous
orange liquid 33B 2-ethylhexylamine 129.25 3.68 Viscous golden
liquid 33C Imidazole 68.05 1.94 Very viscous orange liq. 33D
1-methylimidazole 82.07 2.33 Viscous golden liquid 33E Calcium
oxide 56.08 0.80 Viscous turbid gold slurry
Example 34
(S113-GLY-SA, HHPA, OSA 2:1:3) and (S130-GLY-MHHPA 2:1:3) Salts
Molten 20 g. portions of the products from Examples 14, 15, 16, and
17 were each neutralized with 2 ethylhexylamine (EHAM) by simple
unheated mixing in the amounts shown in TABLE 8.
TABLE-US-00008 TABLE 8 Example Salts Neutralized with
2-ethylhexylamine Glyceride- Sam- Anhydride Acid No. EHAM ple
Adduct mg KOH/g grams Appearance 34A Example 14 70.0 3.23 Soft
yellow wax 34B Example 15 71.6 3.30 Soft yellow wax 34C Example 16
68.3 3.15 Soft yellow wax 34D Example 17 69.6 3.21 Soft off-white
wax
This example demonstrates how partial hydrogenation of a vegetable
triglyceride can increase the melting point of the derived final
product salts. Examples 14-16 originated from Cargill S-113 Wax
(Example 4) and Example 17 derives from Cargill S-130 Wax (Example
5). Since S-113 and S-130 are partially hydrogenated soybean oils,
Example 27D is an un-hydrogenated analog of Example 34A, Example
281 is an un-hydrogenated analog of Example 34B, and Examples 29I
and 31I are replicate un-hydrogenated versions of Example 34D. In
all cases, the un-hydrogenated final salts are liquids whereas the
Example 34 hydrogenated variants are soft waxy solids.
Example 35
(SYBO-GLY-HHPA 2:1:3) Salts
Several salts of the Example 18 product were prepared by
room-temperature mixing of the product with the amines shown in
TABLE 9 in the amounts indicated. Each mixture below is calculated
to give 0.95 mole of amine per mole of acid in the Example 18
product. The appearance and odor of each salt is also noted.
TABLE-US-00009 TABLE 9 Example Amine Salts of Example 18 product
Ex. Appearance/ Amine 18 Amine Physical Sample Amine mw (g) (g)
Form Odor 35A 3-amino-1-propanol 75.11 30.0 2.84 Viscous Mild
yellow oil 35B 2-amino-2-methyl-1-propanol (95%) 89.14 30.0 3.55
Very viscous Mild yellow oil 35C 3-methoxypropyl-amine 89.14 30.0
3.37 Yellow oil Fishy 35D dimethylethanolamine 89.14 30.0 3.37
Yellow oil Amine 35E morpholine 87.12 30.0 3.29 Yellow oil Amine
35F methyldiethanol-amine 119.16 30.0 4.51 Viscous None yellow oil
35G diethylethanol-amine 117.19 30.0 4.43 Golden oil Amine 35H
2-(2-aminoethoxy)-ethanol 105.14 30.0 3.98 Viscous Fishy yellow oil
35I 3-dimethylamino-1-propylamine 100.16 30.0 3.79 Yellow oil Amine
35J t-butylamine 73.14 30.0 2.77 Yellow oil Strong Amine 35K
cyclohexylamine 99.18 30.0 3.75 Stiff yellow None gel 35L
2-ethylhexylamine 129.25 300.0 48.88 Yellow oil Mild 35M
monoethanolamine 61.08 30.0 2.31 Viscous Slight yellow oil Amine
35N triethanolamine 149.19 30.0 5.64 Very viscous None yellow
oil
Comparing the physical appearance of the salts in 35A, 35M, and 35N
in Example 35 to the corresponding salts of Example 28 (28E, 28D,
and 28C) it can be seen that the dibutyltin dilaurate catalyst used
to prepare the precursor diglyceride for Example 35 results in
products having superior homogeneity.
Example 36
(CNTO-GLY-SA 2:1:3) Salts
Amine salts of the Example 19 product were prepared by simple
mixing of 20 g portions of the product with the amines in TABLE 10
in the amounts indicated. The initial appearance of each salt is
also noted.
TABLE-US-00010 TABLE 10 Example Salts of Example 19 Product Sam-
ple Amines mw grams Appearance 36A triethanolamine 149.19 5.02
Off-white wax 36B monoethanolamine 61.08 2.06 Turbid, yellow oil
36C 3-methoxypropylamine 89.14 3.00 Clear, pale yellow oil 36D
diethylethanolamine 117.19 3.95 Clear, golden oil 36E
2-(2-aminoeth- 105.14 3.54 Sl. hazy, pale yellow oxy)ethanol oil
36F 3-(dimethylamino)- 102.18 3.44 Clear, pale yellow propylamine
oil 36G dibutylamine 129.25 4.35 Clear, pale yellow oil 36H
1-octylamine 129.25 4.35 Pale, semi-solid slurry 36I
2-ethylhexylamine 129.25 4.35 Clear, pale yellow oil
All of the salts that were initially clear oils (36C, 36D, 36F,
36G, and 36I) partially froze upon standing at room
temperature.
Example 37
(CNTO-GLY-HHPA 2:1:3) Salts
Eleven amine salts of the Example 20 product were prepared by
simple mixing of 18 g portions of the product with amines in the
amounts shown in TABLE 11. The appearance of each resulting salt
was noted immediately after mixing. Several of the salts that were
initially clear oils (37D, 37F, 37G, 37H, and 37I) partially froze
upon standing; the only exception was the Primene.RTM. 81-R
salt.
TABLE-US-00011 TABLE 11 Example Salts of Example 20 Product Sam-
ple Amines mw grams Appearance 37A triethanolamine 149.19 4.19
Clear yellow oil over turbid gel 37B monoethanolamine 61.08 1.72
Clear yellow oil over turbid gel 37C 3-methoxypropylamine 89.14
2.50 Off-white wax 37D diethylethanolamine 117.19 3.29 Clear,
golden oil 37E 2-(2-aminoeth- 105.14 2.95 Clear yellow oil
oxy)ethanol over turbid gel 37F 3-(dimethylamino)- 102.18 2.87
Clear, pale yellow propylamine oil 37G dibutylamine 129.25 3.63
Clear, pale yellow oil 37H 1-octylamine 129.25 3.63 Clear, pale
yellow oil 37I 2-ethylhexylamine 129.25 3.63 Clear, pale yellow oil
37J Primene .RTM. 81-R 189.89 5.35 Clear, pale yellow oil
Example 38
(CNTO-GLY-MHHPA 2:1:3) Salts
Eleven amine salts of the Example 21 product were prepared by
simple mixing of 18 g portions of the product with amines shown in
TABLE 12 in the amounts shown. The appearance of each resulting
salt was noted immediately after mixing.
TABLE-US-00012 TABLE 12 Example Salts of CNTO-GLY-MHHPA Sam- ple
Amines Mw grams Appearance 38A triethanolamine 149.19 4.19 Clear
yellow oil over turbid gel 38B monoethanolamine 61.08 1.72 Clear
yellow oil over turbid gel 38C 3-methoxypropylamine 89.14 2.50
Off-white wax 38D diethylethanolamine 117.19 3.29 Clear, golden oil
38E 2-(2-aminoeth- 105.14 2.95 Clear yellow oil oxy)ethanol over
turbid gel 38F 3-(dimethylamino)- 102.18 2.87 Clear, pale yellow
propylamine oil 38G dibutylamine 129.25 3.63 Clear, pale yellow oil
38H 1-octylamine 129.25 3.63 Clear, pale yellow oil 38I
2-ethylhexylamine 129.25 3.63 Clear, pale yellow oil 38J Primene
.RTM. 81-R 189.89 5.35 Clear, pale yellow oil
Several of the salts that were initially clear oils (38D, 38F, 38G,
38H, and 38I) partially froze upon standing; the only exception was
the Primene.RTM. 81-R salt.
Example 39
(CNTO-GLY-OSA 2:1:3) Salts
A 2-ethylhexylamine salt of the Example 22 product was prepared by
simple mixing of 18 g of the product with 3.4 g of
2-ethylhexylamine. The product was a clear, pale yellow oil that
froze into a semi-solid waxy slush when cooled.
Example 40
(RPSO-GLY-SA, HHPA, MHHPA, OSA 3:2:5) Salts
Molten 35 gram portions of the products from Examples 23, 24, 25,
and 26 were each neutralized with 2-ethylhexylamine (EHAM) by
simple un-heated mixing according to TABLE 13. All salts were
initially clear oils.
TABLE-US-00013 TABLE 13 Example Salts neutralized with
2-ethylhexylamine Glyceride- Anhydride Acid No. EHAM Sample Adduct
mg KOH/g grams Appearance 40A Example 23 78.0 6.29 Clear golden oil
40B Example 24 74.4 6.00 Clear golden oil 40C Example 25 73.4 5.92
Clear golden oil 40D Example 26 69.4 5.59 Clear golden oil
Example 41
(SYBO-GLY-MHHPA 2:1:3 EHAM) Neutralization Ladder
A duplicate preparation of Example 11 yielded a glyceride
half-ester/half acid having an acid number of 72.4 mg KOH/g. Five
15.0-gram portions of this material were combined with different
amounts of 2 ethylhexylamine (EHAM) according to TABLE 14 to yield
a series having base to acid ratios between 0.8 (80%) and 1.2
(120%). All five materials were clear yellow oils. These examples
demonstrate that amine odors from the final neutralized products
can be minimized or eliminated by using a slight excess of the free
acid to the amine.
TABLE-US-00014 TABLE 14 Effect of Varying Amine Concentration
Sample EHAM grams % Neut Odor 41A 2.00 80% Mild 41B 2.25 90% Mild
41C 2.50 100% Slight amine 41D 2.75 110% Pungent amine 41E 3.00
120% Pungent amine
Evaluation of Corrosion-Inhibiting Compositions
To be applied to a metal substrate the corrosion inhibitor compound
is solubilized in a diluent, such as a volatile organic solvent,
petroleum or vegetable oil, or emulsified in water. The corrosion
inhibitor properties of these compounds (and existing corrosion
inhibitors for comparison) may be assessed using several
established methods, as described below:
1. Accelerated Weathering
Accelerated weathering tests were performed according to ASTM
D4585-07 Standard Practice for Testing Water Resistance of Coatings
Using Controlled Condensation, using a QCT condensation tester,
obtained from Q-Lab Corporation, Westlake, Ohio. The QCT cabinet
applies continuous, controlled-temperature, warm-water condensation
to the test surface. In the test, thin metal panels with a standard
surface finish are held at an angle of 30.degree. from vertical
over a pool of heated water, in an atmosphere at 46.degree. C. As
the metal panels, steel test panels "Q-Panels," were obtained from
Q-Lab Corporation. Two types of panels were employed, both made
from standard low-carbon, cold-rolled steel compliant with ASTM
A1008/1010. Type QD-36 panels have a smooth, polished, bright
finish representative of finely finished metal, whereas type R-36
panels have a rougher, dull-matte finish that is representative of
general sheet-metal applications. These panels, measuring approx.
7.6.times.15.2 cm, were coated by dipping them into various
solutions or emulsions of the corrosion-inhibiting compositions to
be tested. The coated panels were allowed to drip-dry at room
temperature overnight (or longer). The corrosion-inhibiting
properties of the applied coatings were then assessed by placing
the panels on the test stand of the QCT cabinet and periodically
inspecting the panels for the presence of visible rust. Rust spots
that touch an edge of the panel and extend less than 1/8''
(.about.3 mm) inward from the edge are ignored because the panel
edges tend to be scraped during the examination process and this
can lead to removal of the corrosion inhibitor coating and
premature rusting along the edges.
2. Water Displacement and Water Separation
Desirable ancillary properties for a corrosion inhibitor compound
that is to be applied using an organic solvent are the ability of
the solution to displace water and the ability to separate water.
Many metalworking fluids, especially so-called synthetic and
semi-synthetic types and soluble oils, contain significant amounts
of water. An organic solvent solution of a corrosion inhibitor
compound should be able to displace the aqueous metalworking fluid
residues from the metal part which is to be protected. Otherwise,
any aqueous residue that remains on the part may eventually lead to
localized corrosion. Furthermore, it is desirable that the aqueous
phase thus displaced is not emulsified into the corrosion inhibitor
solution, i.e., the displaced aqueous phase should cleanly separate
from the organic corrosion inhibitor solution.
Water separation ability is assessed by combining a solution of the
test substance in an organic solvent with a measured amount of
water, mixing the two phases together, and then timing how long it
takes for the water to fully separate from the organic phase. The
appearance of the water and solvent layers is also noted at the end
of the test, clear aqueous and organic phases suggesting less
intermixing than hazy or turbid phases. Generally, 75 mL of organic
solvent solution and 25 mL of tap water are tested in this manner
in a 100-mL graduated cylinder at room temperature. The cylinder is
inverted six times to mix the water and solvent initially. The
concentration of the test substance in the organic solvent is also
determined.
Performance Results
In the following examples, steel test panels were placed on the QCT
test stand and exposed to a water-saturated atmosphere at
46.degree. C. until rust spots were noted in the critical area
(exposed surface of the panel, 0.3 cm from the edges). The time to
failure (in days) was noted. The steel test panels were of two
types: Type QD-36 panels with a smooth, polished surface, and Type
R-36 with a rough, matte surface. The panel type used in each
example is noted.
Aqueous Emulsion-Applied Corrosion Inhibitors
Example A
Aqueous Emulsion-Applied Corrosion Inhibiting Compositions on
Polished Steel
TABLE 15 shows the performance results for several of the example
corrosion inhibiting compounds applied with water as the carrier
solvent on polished QD-36 steel panels. The test panels were dipped
into freshly-agitated aqueous emulsions of the indicated test
substances and dried at ambient temperature. The table also shows
comparable results for Aqualox.RTM. 2268S rust preventive compound,
available from Lubrizol Corp. Aqualox.RTM. 2268S is designed to be
applied as an aqueous emulsion in this manner.
TABLE-US-00015 TABLE 15 Performance Results for Aqueous
Emulsion-Applied Rust Preventives on Polished Steel Test Anhy- wt.
Sub- dride Neutralizing % in Coated Panel Time to Failure stance
Glyceride Cap Base Emul Appearance (days) 29A SYBO- MHHPA KOH
10.0%.sup.a Edge dewetting 9 GLY 2:1 15.0%.sup.a Edge dewetting
28.sup.b 20.0%.sup.a Edge dewetting 0.2 0.04 29B SYBO- MHHPA NaOH
6.0%.sup.a Edge dewetting 0.3 GLY 2:1 8.0%.sup.a Edge dewetting 1.0
10.0%.sup.a Edge dewetting 49 31 29C SYBO- MHHPA triethanolamine
10.0% Edge dewetting 0.1 GLY 2:1 10.0% Mottled 0.2 0.2 15.0%
Mottled 1.1 1.1 20.0% Uniform film 5.0.sup.c 5.1.sup.c 29D SYBO-
MHHPA monoethanolamine 10.0%.sup.a Edge dewetting 0.1 GLY 2:1
20.0%.sup.a Moderate dewetting 0.1 0.04 29E SYBO- MHHPA
diethylethanolamine 10.0%.sup.a Uniform glossy .sup.c .sup.c GLY
2:1 15.0%.sup.a Uniform glossy .sup.c .sup.c 20.0%.sup.a Uniform
film 5.1.sup.d 5.1.sup.d 30A SYBO- MHHPA NH.sub.2(CH.sub.2).sub.3OH
10.0%.sup.a Edge dewetting >5 >5 GLY 2:1 30B SYBO- MHHPA
NH.sub.2(CH.sub.2).sub.3Ome 10.0%.sup.a Edge dewetting >5 >5
GLY 2:1 30C SYBO- MHHPA AEE 10.0%.sup.a Edge dewetting >5 >5
GLY 2:1 30D SYBO- MHHPA NH.sub.2(CH.sub.2).sub.5OH 10.0%.sup.a
Severe dewetting >5 1.0 GLY 2:1 30E SYBO- MHHPA DMEA 10.0%.sup.a
Edge dewetting >5 >5 GLY 2:1 30F SYBO- MHHPA TIPA 10.0%.sup.a
Severe dewetting 0.1 0.1 GLY 2:1 Aqualox .RTM. 2268S 10.0% Moderate
dewetting 0.04 0.1 10.0% Moderate dewetting 0.1 0.1 10.0% Moderate
dewetting 0.1 0.1 Notes for TABLE 15: .sup.aSome separation or
creaming of emulsion over time .sup.bEdges (non-critical area)
failed rapidly and completely due to edge dewetting. .sup.cLeft
gray, non-rust stain spots on panel. Appeared early in test.
.sup.dFailure called on brown spots that appeared to be rust but
were actually oily spots. Left gray non-rust stains under these
spots.
Examples 30A-F at 10% in water were tested side-by-side with
Aqualox.RTM. 2268S at 10% for five days. At the end of the five-day
test, the exposed panel surfaces were cleaned with isopropyl
alcohol and compared side-by-side. Visual rank-ordering of the
panels from best to worst was as follows: 30C>30A,
30B>Aqualox.RTM. 2268S>30E>30D>>30F
Observations on the individual panels in this side-by-side
comparison were as follows:
30A: Light discoloration band in center of panel
30B: Light discoloration band in center of panel
30C: Very faint discoloration
30D: Mottled appearance
30E: Obvious stains in a streaked pattern, center of panel
30F: Severe stain spots, center discoloration, and edge rust
Aqualox.RTM. 2268S: Edge rust (.about.0.6 cm) and patchy top
rust
Example B
Aqueous Emulsion-Applied Corrosion Inhibiting Compositions on Rough
Steel
TABLE 16 shows the performance results for several of the example
corrosion inhibitor compounds on rough-finish R-36 steel panels.
The test substances were again applied as aqueous emulsions, then
dried. Aqualox.RTM. 2268S was again used as a comparative example
of a conventional emulsion-type corrosion inhibitor.
TABLE-US-00016 TABLE 16 Comparative Results for Aqueous
Emulsion-Applied Corrosion Inhibiting Compositions on Rough Finish
Steel Test Anhy- Time to Sub- dride Neutralizing wt. % in Failure
stance Glyceride Cap Base Emulsion (days) 36C CNTO-GLY SA
NH.sub.2(CH.sub.2).sub.3Ome 5.0%.sup.a 9.3 2:1 10.0%.sup.a 10
20.0%.sup.a >28 36D CNTO-GLY SA diethyl- 5.0%.sup.a 10 2:1
ethanolamine 10.0%.sup.a 9.3 20.0%.sup.a >28 36F CNTO-GLY SA
DMAPA 5.0%.sup.a 9.0 2:1 10.0%.sup.a 9.3 20.0%.sup.a 17 37F
CNTO-GLY HHPA DMAPA 5.00%.sup.a 8.0 2:1 10.0%.sup.a >27
20.0%.sup.a >27 Aqualox .RTM. 2268S 10.0% 9.0, 9.3
All the coated panels had a uniform matte appearance.
In TABLE 16 above, Examples 36C, 36D, 36F, and 37F at 5%, 10%, and
15% in water were tested side-by-side against 10% Aqualox.RTM.
2268S on R-36 panels for 28 days. At the end of the test, the
exposed panel surfaces were compared side-by-side. In all cases,
the results suggest that the Example compounds protected the test
panels better than the reference Aqualox.RTM. 2268S at equal or
lower concentration (bearing in mind that such accelerated tests do
not always accurately predict results for actual exposures). Prior
to running these tests, the average film thickness of the dried
rust preventive films was estimated for Example compounds 36C, 36D,
and 36F and Aqualox.RTM. 2268S by weighing the panels before and
after coating and knowing the approximate density of the dry
corrosion inhibiting compounds. These estimated film thicknesses as
a function of wt. % of the test substance in the applied emulsion
are shown in the FIGURE. This suggests that the superior rust
preventive performance of Examples 36C, 36D, and 36F relative to
Aqualox.RTM. 2268S is accomplished at equal or lower film
thickness.
Example C
Example 27 Compounds in an Emulsion Base-Type Corrosion Inhibiting
Composition
TABLE 17 shows the results of using two of the compounds
illustrated in Example 27 as corrosion inhibitors applied as part
of an emulsion base package with water as the carrier solvent. The
emulsion base package consisted of 25 wt. % of the test substance,
5 wt. % diethylene glycol monobutyl ether, and 70 wt. % 200 SUS
naphthenic oil. The emulsion base package was then diluted with
water to form an emulsion that was used to coat type QD-36 test
panels which were air-dried prior to testing. The last two lines of
Example C show comparison results for Aqualox.RTM. 2290 AS, a
corrosion inhibitor compound available from Lubrizol Corp. Aqualox
2290 AS is designed to be applied as part of an emulsion base
package in this manner.
TABLE-US-00017 TABLE 17 Comparative Results for Emulsion Base-type
Corrosion Inhibiting Compositions Test Anhy- Emul. Sub- dride
Neutralizing Base Solution Coated Panel Days to stance Glyceride
Cap Base Wt. % Appearance Appearance Failure 27B SYBO- SA
triethanolamine 10.0% Emulsion.sup.a Oily w. streaks 23 23 GLY 2:1
20.0% Emulsion.sup.a Oily w. waves 28 28 27C SYBO- SA
diethylethanolamine 10.0% Emulsion.sup.a Oily, mottled 21 21 GLY
2:1 20.0% Emulsion.sup.a Oily, slightly 21 21 mottled Aqualox .RTM.
2290AS 10.0% Tan Oily w. dry 2 2 emulsion edges 20.0% Tan Uniform
oily 21 21 emulsion Note: .sup.aSlight separation or creaming of
emulsion over time.
Solvent and Oil-Applied Corrosion Inhibitors
In the following examples, the corrosion inhibitor compounds are
dissolved in volatile organic solvents or non-volatile oils for
application to the test panels. As with the aqueous
emulsion-applied corrosion inhibitors described previously, the
coated test panels are allowed to air dry prior to testing on the
QCT stand.
Example D
Ca-Salt of Glyceride Half-Acid Ester Vs. Amine Salt of Glyceride
Half-Acid Ester
TABLE 18 compares three corrosion inhibiting compositions applied
to polished QD-36 steel test panels using mineral spirits as the
carrier solvent. A Ca-salt glyceride half-acid ester and an amine
salt glyceride half-acid ester were used as the exemplary
compounds. Alox.RTM. 165, a calcium sulfonate-based corrosion
inhibitor compound commercially available from Lubrizol Corporation
was used for comparison. Alox.RTM. 165 is designed to be applied
using volatile organic solvents in this manner, and 5 wt. % of this
material in solution is a typical recommended usage level.
TABLE-US-00018 TABLE 18 Comparative Results for Solvent-Based
Corrosion Compositions Test Anhy- Neutral- wt. Sub- dride izing %
in Solution Days to stance Glyceride Cap Base Soln Appearance
Failure 29I SYBO- MHHPA EHAM 2.5% Clear, 4.9 5.0 GLY 2:1 colorless
29J SYBO- MHHPA CaO 2.5% Hazy, slight 2.2 2.2 GLY 2:1 precip. Alox
.RTM. 165 5.0% Clear, 1.0 1.9 brown
All the coated panels had a uniform, glossy appearance.
Example D indicates that the organic amine salt (29I) gives over
twice the protection time as the corresponding calcium salt (29J).
However, the calcium salt was not completely soluble in mineral
spirits. Calcium salts have traditionally been used in many
existing corrosion inhibitor compounds. Example 29I product gives
significantly longer protection than the Alox.RTM. 165 corrosion
inhibitor, under the test conditions, when used at one-half the
application level.
Example E
Inorganic Salt Vs. Hydrophilic Amine Salt Vs. Hydrophobic Amine
Salt
The QD-36 type test panels and mineral spirits as the carrier
solvent were again used for testing the corrosion inhibitor
compounds. All the coated panels had a uniform, glossy
appearance.
The results in TABLE 19 suggest that for an organic solvent-applied
corrosion inhibitor application, hydrophobic amines such as
2-ethylhexylamine (EHAM) are better than hydrophilic amines, as
exemplified in this case by 3 methoxypropylamine, for the choice of
the neutralizing base (all samples of the Example 29 products use
SYBO-GLY 2:1 as the glyceride and MHHPA as the anhydride cap). This
example also suggests that both the hydrophilic and hydrophobic
amine types are superior to inorganic bases, here exemplified by
sodium hydroxide. Regardless of the neutralizing base chosen, the
glyceride-cyclic carboxylic acid anhydride adducts outperform the
existing material, Alox.RTM. 165, under the test conditions.
TABLE-US-00019 TABLE 19 Comparative Results for Inorganic salt,
Hydrophilic Amine Salt and Hydrophobic Amine Salt Test wt. Sub-
Neutralizing % in Solution Days to stance Base Soln Appearance
Failure 29B NaOH 2.5% Hazy bottom layer 4.0 6.0 30B
NH.sub.2(CH.sub.2).sub.3Ome 2.5% Clear, colorless 6.0 6.0 29I
2-ethyl hexyl- 1.75% Clear, colorless >42 >42 amine (EHAM)
1.50% Clear, colorless 16 >42 1.25% Clear, colorless 24 >42
1.00% Clear, colorless 7.9 24 Alox .RTM. 165 5.0% Clear, gold 1.9
4.0
Example F
Concentration Ladder to Establish Concentration Threshold
Smooth QD-36 panels were used as the substrate and the test
substance was applied at different concentrations using Isopar M as
the carrier solvent. Isopar M is a 92.degree. C. flash point
isoparaffinic solvent commercially available from Exxon Mobil
Chemical Company. Results are shown in TABLE 20.
TABLE-US-00020 TABLE 20 Comparative Results for Different
Concentrations of Compound Test Anhydride Neutralizing wt. %
Solution Days to Substance Glyceride Cap Base in Soln Appearance
Failure 30E SYBO- MHHPA dimethyl- 4.0% Hazy 14 GLY ethano- 3.0%
Turbid 14 2:1 lamine 2.0% Turbid 1.0 1.0% Turbid 0.17 0.5% Hazy
0.13 0.25% Hazy 0.07
All coated panels had a uniform, glossy appearance.
TABLE 20 illustrates that the rust preventive performance of this
particular substance (Example 30E) increases dramatically at an
application level of about 2 wt. %. Above this threshold the
performance is not seen to increase significantly. It will be
expected that for each particular corrosion inhibitor compound
described herein it is desirable to apply the material at a level
at or above its concentration threshold in order to achieve optimal
rust protection, which may differ from that for the 30E corrosion
inhibitor compound.
Example G
Effect on Protection Time Above Threshold
Polished QD-36 panels and Isopar M as the application solvent were
used. Samples of the products of Example 27 (using SYBO-GLY 2:1 as
the glyceride and SA as the anhydride cap) were combined with the
solvents in different concentrations. All of the tests shown in
TABLE 21 are above the concentration threshold for the respective
test substance. For some samples, duplicate test panels were
tested. The results suggest that increasing the application level
above the concentration threshold does not yield a significant
improvement in the protection time on polished surfaces such as the
QD-36 panels under the test conditions used.
TABLE-US-00021 TABLE 21 Comparative Results of Tests Above the
Concentration Threshold Test wt. Sub- Neutralizing % in Solution
Days to stance Base Soln Appearance Failure 27C
diethyl-ethanolamine 5.0% Clear, yellow 21 2.5% Clear, yellow 24
27D 2-ethyl-hexylamine 5.0% Clear, colorless 21 2.5% Slightly hazy
21 27E PA-16 5.0% Clear, colorless 23 2.5% Clear, colorless 23 27H
imidazole 5.0% Clear.sup.a 24 21 4.0% Clear.sup.a 18 25 3.5%
Clear.sup.a 21 21 3.0% Clear.sup.a 18 21 2.5% Clear.sup.a 21 21
2.0% Clear.sup.a 18 18 27I 1-methyl imidazole 4.0% Hazy 23 23 3.0%
Hazy 21 22 2.0% Hazy 24 24 27J 2-methyl imidazole 4.0% Clear,
colorless 17 23 3.0% Clear, colorless 14 21 2.0% Clear, colorless
14 17 Note: .sup.aSome haze forming in the solution over time.
Example H
Concentration Effect for Soy Vs. Hydrogenated Soy on Rough
Panels
In this example, rough R-36 panels were used as the test substrate.
The corrosion inhibitors were applied as solutions in mineral
spirits and dried overnight. Results are shown in TABLE 22. The
results suggest that the corrosion inhibitor derived from soybean
oil glyceride gives significantly longer time to failure than the
corresponding hydrogenated soybean oil glyceride. This example also
suggests that about 1 wt. % of the Example 29I product performs
almost as well as 5 wt. % of the Alox.RTM. 165 corrosion inhibitor
on the type R-36 panels under these conditions. Furthermore it may
be noted that comparing the results for the Example 29I product in
this example with analogous results on polished QD-36 panels, a
higher application level is required to achieve the same protection
time on the rough R-36 panels. Also, leveling off of the protection
time above a threshold concentration (as was seen on polished
panels) is not observed on the rough R-36 panels.
TABLE-US-00022 TABLE 22 Concentration Effect for Soy vs.
Hydrogenated Soy on Rough Panels Test Anhydride Neutralizing wt. %
Solution Days to Substance Glyceride Cap Base in Soln Appearance
Failure 29I SYBO- MHHPA 2-ethylhexylamine 1.0% Clear, colorless 4.2
GLY 2:1 (EHAM) 2.0% Clear, colorless 19 4.0% Clear, colorless 38
6.0% Clear, colorless >46 34D S130- MHHPA 2-ethylhexylamine 1.0%
Clear, colorless 0.08 GLY 2:1 (EHAM) 2.0% Clear, colorless 0.13
4.0% Clear, colorless 6.0 6.0% Clear, colorless 10 Alox .RTM. 165
5.0% Clear, brown 5.0
Example I
Three Glyceride-Anhydride Adducts Neutralized with Four Bases
In this example, polished QD-36 test panels were coated with 1 wt.
solutions of various example corrosion inhibitors in mineral
spirits. Results are shown in TABLE 23. Failure times that are
noted as being less than four days are greater than 1.3 days
(failures occurred over a weekend).
TABLE-US-00023 TABLE 23 Comparative results for Three
Glyceride-Anhydride Adducts Neutralized with Four Bases Test Sub-
Anhydride Neutralizing Solution Coated Panel Days to stance
Glyceride Cap Base Appearance Appearance Failure 28A SYBO- HPPA KOH
Clear, Uniform 0.13 0.13 GLY 2:1 colorless glossy 28F
NH.sub.2(CH.sub.2).sub.3Ome Clear, Uniform 1.3 <4 colorless
glossy 28I EHAM Clear, Uniform <4 4.0 colorless glossy 28J CaO
Hazy, slight Matte w. precipitate particles <4 4.0 29A SYBO-
MHHPA KOH Clear, Uniform 0.33 0.29 GLY 2:1 colorless glossy 30B
NH.sub.2(CH.sub.2).sub.3Ome Clear, Uniform 1.3 <4 colorless
glossy 29I EHAM Clear, Uniform <4 <4 colorless glossy 29J CaO
Hazy, slight Matte w. 1.3 <4 precipitate particles 32A SYBO-
MHHPA KOH Clear, Uniform 0.13 0.21 GLY 1:1 colorless glossy 32F
NH.sub.2(CH.sub.2).sub.3Ome Clear, Uniform <4 <4 colorless
glossy 32I EHAM Clear, Uniform <4 <4 colorless glossy 32J CaO
Clear, Uniform 1.0 1.3 colorless glossy
In the Example I series, three different glyceride-anhydride
adducts were each neutralized with four different bases: potassium
hydroxide, 3-methoxypropylamine (a hydrophilic amine),
2-ethylhexylamine or EHAM (a hydrophobic amine), and calcium oxide.
For all three glyceride-anhydride combinations, the KOH salt gave
the least rust protection. The other three salts were more
comparable in their protection times, however, the Ca salts were
not entirely soluble in mineral spirits for the first two
glyceride-anhydride combinations. The third combination, having a
lower ratio of soybean oil to glycerin in the glyceride, gave a
soluble Ca salt, but this salt failed to give as much rust
protection as the amine salts. The results suggest, therefore, that
organic amine salts give a superior combination of solvent
solubility and rust protection when compared to the equivalent
inorganic salts.
Example J
Three Glycerides with Four Different Anhydride Caps,
2-Ethylhexylamine Salts
R-36 panels were used as the test substrate. The test substances
were all applied to the panels as 0.75 wt. % solutions in mineral
spirits and dried for three days prior to testing. In all cases,
the neutralizing base is 2-ethylhexylamine. TABLE 25 shows the
results obtained.
This example suggests that the best-performing anhydride cap varies
depending on the glyceride with which it is reacted. This example
further suggests that the coconut oil-derived corrosion inhibitors
do not protect as well (taken as a group) as do the soy and
rapeseed oil-derived products.
Water separation tests were also conducted on the Example J
materials. In the water separation test, 75 mL of a 0.75 wt. %
solution of the test substance is combined with 25 mL of water in a
graduated cylinder. The cylinder is inverted six times, and then
allowed to stand. The time for greater than 24 mL of water to
separate as a bottom phase is noted in TABLE 25, along with the
appearance of the water and solvent layers after separation.
Desirable performance in this test is fast water separation
yielding clear aqueous and solvent phases. The data suggests that
the succinic anhydride-capped materials taken as a group have
inferior water separation. The OSA-capped materials leave a foam
"cuff" at the interface between the aqueous and solvent phases in
the water separation test.
TABLE-US-00024 TABLE 25 Comparative Results for Three Glycerides
with Four Caps, 2-ethylhexylamine Salts Water Test Anhydride Days
to Separation Substance Glyceride Cap Failure Time (sec) Notes 36I
CNTO-GLY 2:1 SA 2.3 450 Slightly hazy water and turbid solvent 37I
HHPA 1.1 220 Clear water, hazy solvent 38I MHHPA 1.0 220 Clear
water with loose emulsion layer and turbid solvent 39 OSA 2.3 200
Clear water, clear solvent with foam "cuff" at interface 22D
SYBO-GLY 2:1 SA 3.1 >1200 Hazy water and solvent emulsion 28I
HHPA 3.0 150 Clear water, hazy solvent 31I MHHPA 3.0 120 Clear
water and clear solvent 40A RPSO-GLY 3:2 SA 2.3 >1200 Hazy water
and solvent emulsion 40B HHPA 3.1 120 Clear water and clear solvent
40C MHHPA 3.1 110 Clear water and clear solvent 40D OSA 2.3 300
Clear water, clear solvent with foam "cuff" at interface
Example K
Effect of Solvent on Performance
The Example 29I product SYBO-GLY 2:1 as the glyceride, MHHPA as the
anhydride cap, and 2-ethylhexyl amine (EHAM) as the neutralizing
base) was applied as a corrosion inhibitor to type QD-36 polished
panels using different organic solvents and different
concentrations. The results are shown in TABLE 26, with the
Alox.RTM. 165 corrosion inhibitor used for comparison. The results
suggest that the Example 29I product significantly outperforms the
existing corrosion inhibitor Alox.RTM. 165 on smooth QD-36 panels
at equal or lower use levels in mineral spirits. This example
further suggests that the performance of the Example 29I product is
deleteriously affected when non-volatile oils are used to apply the
corrosion inhibitor to the test panel. A large jump in the
protection time was observed for the Example 29I product applied
with mineral spirits from 0.75% to 2%. This is another example of
the concentration threshold effect on the polished QD-36
panels.
TABLE-US-00025 TABLE 26 Comparative results for Effect of Solvent
on Performance wt. % Days to Test Substance Diluent in Soln Failure
29I Mineral Spirits 5.0% 52 >65 4.0% 52 >65 3.0% 23 >65
2.0% 11 21 0.75% 1.0 1.0 0.50% 0.13 0.15 0.25% 0.08 0.08 0.13% 0.05
0.05 Isopar M 2.5% 21 0.23 Paraffinic Oil, 100 SUS 2.5% 0.23 0.13
Soybean Oil 2.5% 0.03 0.03 Alox .RTM. 165 Mineral Spirits 5.0% 1.1
2.0 5.0% 1.3 2.0
Example L
Corrosion Inhibitors Using ODSA as the Anhydride
In this example, QD-36 panels were used and Isopar M as the
application solvent for the test substances. Results are shown in
TABLE 27. This example suggests that octadecenyl succinic anhydride
(ODSA) as the anhydride reactant results in products that do not
perform better than the Alox.RTM. 165 corrosion inhibitor (although
a lower concentration was used). Without being bound by any
particular theory, it is hypothesized that, compared with other
anhydrides, the bulky octadecenyl moiety in close proximity to the
carboxylate functionality may interfere with the ability of the
carboxylate to bind effectively with the surface of the steel
substrate, therefore resulting in a less-protective film.
TABLE-US-00026 TABLE 27 Comparative results for Corrosion
Inhibitors Using ODSA as the Anhydride Test Anhy- wt. Coated Sub-
dride Neutralizing % in Solution Panel Days to stance Glyceride Cap
Base Soln Appearance Appearance Failure 33A SYBO- ODSA diethyl-
2.5% Clear, Note.sup.a <4 <4 GLY 1:2 ethanolamine yellow 33B
EHAM 2.5% Clear, Note.sup.a 1.0 <4 yellow 33C imidazole 2.5%
Clear, Note.sup.a <4 <4 yellow 33D 1-methylimidazole 2.5%
Clear, Note.sup.a <4 <4 yellow 33E CaO 2.5% Turbid Note.sup.a
<4 <4 Alox .RTM. 165 5.0% Clear, Uniform <4 <4 brown
glossy Note: .sup.aGlossy with ~1.3 cm darker band at bottom of
panel
Example M
Corrosion Inhibitors Using Hydrogenated Soybean Glyceride
In this example, mineral spirits was used as the carrier solvent
for application of the corrosion inhibitors to QD-36 panels.
Results are shown in TABLE 28. This example suggests that good
corrosion inhibitors can be produced from partially hydrogenated
soybean oil (in this instance Cargill S-113 Wax), however, the
partially hydrogenated soybean oil appears to confer no significant
performance advantage over soybean oil itself.
TABLE-US-00027 TABLE 28 Comparative results for Corrosion
inhibitors Using Hydrogenated Soybean Glyceride Test Anhydride
Neutralizing wt. % Solution Days to Substance Glyceride Cap Base in
Soln Appearance Failure 29I SYBO- MHHPA 2-ethylhexylamine 1.0%
Clear, 2.0 2.0 GLY 2:1 (EHAM) colorless 34B S113- HHPA 1.0% Clear,
1.0 1.0 GLY 2:1 colorless 34C S113- OSA 1.0% Clear, 1.0 1.3 GLY 2:1
colorless 34A S113- SA 1.0% Clear, >2.0 2.0 GLY 2:1 colorless
Alox .RTM. 165 5.0% Clear, 1.0 1.3 brown
Example N
Effect of Neutralization
Examples 41A-E were each dissolved at 1 wt. % in mineral spirits
and these solutions were used to coat QD-36 panels which were
tested on the QCT for three days after drying. At the end of the
three-day test, the panels were visually compared. All five panels
were past failure at that point, with partial rust coverage on all
of the panels. Rank ordering of these panels from best to worst was
C>B.about.D>A.about.E. There was very little difference in
the rust coverage on panels 41B, 41C, and 41D. This example
suggests that 10% under- or over-neutralization of the
glyceride-cyclic carboxylic acid anhydride adducts by an organic
amine does not markedly affect the rust preventive performance.
Slight under-neutralization (i.e., an excess of acid) is therefore
practical because odors due to free amine are minimized.
Example O
Effect of Solvent Volatility
For this example, Example compound 29I (SYBO-GLY 2:1 as the
glyceride, MHHPA as the anhydride cap and 2-ethylhexyl amine (EHAM)
as the neutralizing agent) was dissolved at 10 wt. % in a series of
hydrocarbon solvents of varying volatility as well as in a
non-volatile paraffinic oil. These solutions were used to coat
rough R-36 panels. The Exxsol.TM. solvents shown in TABLE 29 are
commercially available dearomatized aliphatic solvents available
from ExxonMobil Chemical Company. The boiling ranges and
evaporation rates of these solvents (relative to butyl acetate)
were taken from ExxonMobil literature. Results shown in TABLE 29
suggest that the protection time increases as the volatility of the
solvent increases. The protection time using the non-volatile
paraffinic oil was relatively low. These results suggest that
residual solvent or oil may have a deleterious impact on the
corrosion inhibiting films.
TABLE-US-00028 TABLE 29 Effect of Solvent Volatility Test Solv.
Solv. Evap Rate Sub- lower upper (BuAc = Days to stance Solvent
b.p. (.degree. C.) b.p. (.degree. C.) 100) Fail 29I Exxsol D40 161
198 18 68 Exxsol D60 190 211 6 46 Exxsol D80 208 234 1.8 18 Exxsol
D95 225 239 0.7 19 Paraffinic Oil, 100 Neutral <3
Example P
Effect of Hydrophobic Amine Choice
In this example, mineral spirits was used as the carrier solvent
for applying the test substances to R-36 panels. Results are shown
in TABLE 30. This example shows that the protection time is
influenced by the choice of the neutralizing amine, even when
structurally similar hydrophobic amines are compared.
TABLE-US-00029 TABLE 30 Effect of Hydrophobic Amine Choice Test
Sub- Anhydride Neutralizing wt. % in Days to stance Glyceride Cap
Base Soln Failure 31E SYBO-GLY MHHPA Bu.sub.3N 1.0% 41 31F 2:1
Bu.sub.2NH 1.0% >60 31H octylamine 1.0% >60 31I EHAM 1.0% 26
31J Primene 81-R 1.0% 28 Alox .RTM. 165 -- 5.0% 60
Example Q
HHPA Vs MHHPA with Four Hydrophobic Amines
In this example, mineral spirits was again used as the carrier
solvent for 0.75 wt. % solutions of the test substances applied to
R-36 panels. The results are shown in TABLE 31. For this coconut
oil diglyceride, the results suggest that HHPA performs better than
MHHPA as the anhydride cap and that the three primary amines
outperform the secondary dibutylamine as the neutralizing base.
TABLE-US-00030 TABLE 31 Comparative Results for HHPA vs MHHPA with
Four Hydrophobic Amines Test Anhydride Substance Glyceride Cap
Neutralizing Base Days to Failure 37G CNTO-GLY HHPA Bu.sub.2NH 1.1
37H 2:1 octylamine 2.0 37I EHAM 2.0 37J Primene 81-R 1.0 38G MHHPA
Bu.sub.2NH 0.24 38H octylamine 1.0 38I EHAM 1.1 38J Primene 81-R
1.2
Dual-Use Corrosion Inhibitors
Example R
SYBO-Gly-HHPA 2:1:3 Various Amine Salts, Emulsion and Solvent
Applied
Various amine salts from Example 35 were used both as
emulsion-applied corrosion inhibitors at 5 wt. % in water and also
as solvent-applied corrosion inhibitors at 0.75 wt. % in
Exxsol.RTM. D-40 Fluid. Results are shown in TABLE 32. Where no
test is indicated, either the aqueous emulsion did not have
satisfactory stability, or the material was not totally soluble in
the Exxsol.RTM. D-40. TABLE 32 shows several instances, however, of
amine salts that exhibit both adequate emulsion stability and
solvent solubility. These salts can therefore be used either as
emulsion-applied corrosion inhibitors or as solvent-applied
corrosion inhibitors. Aqualox.RTM. 2268S and Alox.RTM. 165
corrosion inhibitors at 10 wt. % and 5 wt. % respectively were used
as comparative emulsion-type and solvent-type products. Test
substances 35A, C, I, and J gave comparable or greater protection
time under the test than these commercial products using both
application methods, despite the lower use levels. This example
also illustrates the influence of the amine neutralizing agent on
the solubility properties of the corrosion inhibitor compounds as
well as the protection time.
TABLE-US-00031 TABLE 32 Comparative results for SYBO-Gly-HHPA 2:1:3
with Various Amine Salts, Emulsion and Solvent Applied 5 wt. % in
0.75 wt. % in Water Exxsol D-40 .TM. Test Coated Panel Days to
Coated Panel Days to Substance Neutralizing Amine Appearance
Failure Appearance Failure 35A 3-amino-1-propanol Mottled >37
Note a 7 35B 2-amino-2-methyl-1- Mottled 21 Not tested -- propanol
35C 3-methoxypropylamine Mottled 28 Note a 7 35D
dimethylethanolamine Mottled >37 Not tested -- 35E morpholine
Mottled >37 Not tested -- 35F methyldiethanolamine Mottled 28
Note a 3 35G diethylethanolamine Mottled >37 Not tested -- 35H
2-(2-aminoethoxy)ethanol Mottled 24 Not tested -- 35I
3-dimethylamino-1- Mottled >38 Note a 20 propylamine 35J
t-butylamine Mottled 15 Note a 20 35K cyclohexylamine Not tested --
Note a 3 35L 2-ethylhexylamine Not tested -- Note a 20 35M
monoethanolamine Mottled 32 Note a 6 35N triethanolamine Mottled 21
Note a 1 Aqualox .RTM. 2268S, 10% in water Uniform, slight 9 -- --
edge dewetting Alox .RTM. 165, 5% in Exxsol .TM. -- -- Uniform dark
7 D-40 Fluid Note: a. Uniform with ~1.3 cm darker band at bottom of
panel.
Example S
SYBO-Gly-HHPA 2:1:3 Various Amine Salts, Solution Properties
The solution and emulsion properties of the materials shown in
Example 35 are described in TABLE 33. The appearances of each
material at 0.75 wt. % in Exxsol D-40.TM. fluid and of 5 wt. %
emulsions in water are also noted. The amount of cream (volume %)
on top of the emulsion was measured after centrifuging a portion of
the emulsion for 10 minutes at 2500 rpm. A water separation test
was performed on each of the 0.75 wt. % Exxsol D-40.TM. solutions.
A 40-mL portion of the solution was combined with 10 mL of tap
water in a 50-mL graduated cylinder which was inverted six times.
The amount of time for 10 mL of aqueous layer to separate was noted
along with the appearance of the aqueous and solvent layers. The
results suggest that the solubility characteristics, both in
organic solvents and as aqueous emulsions, are influenced by the
choice of the amine neutralizing agent.
TABLE-US-00032 TABLE 33 SYBO-Gly-HHPA 2:1:3 Various Amine Salts.
Solution Properties Appearance Test 0.75% in H.sub.2O Sub- Exxsol
.TM. 5% in Sep. stance Amine D-40 H.sub.2O (sec) Note 35A
3-amino-1-propanol Clear 2% Cream 160 a 35B 2-amino-2-methyl-1-
Turbid 1% Cream 248 b propylamine 35C 3-methoxypropylamine Clear 3%
Cream 280 c 35D dimethylethanolamine Hazy 2% Cream 185 b 35E
morpholine Hazy 2% Cream 180 d 35F methyldiethanolamine Clear 1%
Cream 140 a 35G diethylethanolamine Hazy 2% Cream >300 c 35H
2-(2-aminoethoxy) Turbid 1% Cream 120 a ethanol 35I
3-dimethylamino-1- Clear 1% Cream 210 e propylamine 35J
t-butylamine Clear 2% Cream 125 f 35K cyclohexylamine Clear
Separated 210 f 35L 2-ethylhexylamine Clear Separated 60 a 35M
monoethanolamine Clear 1% Cream 115 a 35N triethanolamine Clear 1%
Cream 134 a Notes: a. Clear water and clear solvent. b. Clear
water. Solvent has fine droplets and ~5% hazy bottom layer. c. Hazy
water and turbid solvent. d. Clear water and turbid solvent. e.
Clear water and clear solvent with stable foam cuff. f. Clear water
and turbid solvent with stable foam cuff.
As the examples illustrate, soybean oil transesterified with
glycerin in a 2:1 mole ratio using dibutyltin dilaurate as a
catalyst at 0.35 wt. % in the reaction mixture at a temperature of
180.degree. C. yields a soy diglyceride mixture (Example 18) which
when subsequently reacted with hexahydrophthalic anhydride at a
mole ratio of about 0.90 moles of anhydride per mole of free
hydroxyl groups in the diglyceride gives a soy diglyceride
half-acid/half-ester having an acid number of about 74-75 mg KOH/g
(Example 35). This half-ester/half-acid neutralized with
monoethanolamine (Example 35M) gives a corrosion inhibitor organic
salt that is soluble in organic solvents and also emulsifiable in
water (Example S). Solutions or emulsions of this material
containing from about 0.5 to 10 wt. % of the salt provide excellent
thin-film rust protection to ferrous metals when exposed to
atmospheric moisture (Example R).
The disclosures of all references mentioned herein are expressly
incorporated herein by reference in their entireties.
The term "alkyl group" refers to a saturated, linear or branched
group, which generally has between 1 and 24, e.g., between 1 and
16, typically between 1 and 14 carbon atoms and is bound to the
rest of the molecule by a single bond, including, for example and
not restricted to, methyl, ethyl, isopropyl, isobutyl, tert-butyl,
heptyl, octyl, decyl, dodecyl, lauryl, hexadecyl, octadecyl, amyl,
2-ethylhexyl, 2-methylbutyl, 5-methylhexyl and similar.
The term "alkenyl group" refers to a linear or branched group,
which generally has between 2 and 24, e.g., 2-16, typically 2-14
carbon atoms, with one or more carbon-carbon double bonds,
conjugated or unconjugated, which is bound to the rest of the
molecule by a single bond, including, for example and not
restricted to, vinyl, oleyl, linoleyl and similar groups.
It will be appreciated that variants of the above-disclosed and
other features and functions, or alternatives thereof, may be
combined into many other different systems or applications. Various
presently unforeseen or unanticipated alternatives, modifications,
variations or improvements therein may be subsequently made by
those skilled in the art which are also intended to be encompassed
by the following claims.
* * * * *